Strong Reactions to 'Antidepressants Ineffective' Study
"People are completely missing the point of this paper and all the other recent re-investigations, the true social and clinical consequences of them. For example: they're saying antidepressants are no good. Ok. What do you think doctors are going to use instead? Psychoanalysis? Nothing? They're going to prescribe antipsychotics. Are you listening to me? I'm not even saying this is clinically wrong to do, but do you not see the setup?"
Ben Goldacre at Badscience, meanwhile, like some of the commenters here on PsyBlog, pointed out it didn't tell us much we didn't already know. But the real target of Ben's article is the failure to successfully regulate Big Pharma:
"This new study - published, ironically, in an open access journal - tells a fascinating story of buried data, and of our collective failure, as a society, over half a century, to adequately regulate the colossal $550bn pharmaceutical industry."
He also pointed out several errors in the reporting of the study, one of which I made myself by talking about SSRI antidepressants. In fact two of the drugs included were nefazodone and venlafaxine, neither of which are SSRIs. I made the mistake of trusting the 'editor's summary' that is published with the article in PLoS Medicine.
Finally for an international perspective on this story, Furious Seasons points out the near-silence on this study in the US:
"I am stunned that in Seattle--the most depressed city in America--that neither of the daily newspapers ran so much as an AP wire account of the study--at least as far as I know. That's weird. But then the New York Times has been mum to date as well. That's even weirder."
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Labels: Depression
Creativity: Action is Everything
In a recent series on the hidden workings of our minds I noted that scientists, artists and writers often have considerable difficulty explaining their thought processes. isabella replies that perhaps this difficulty is a necessary part of the process:
"perhaps these accounts of thought processes that are "disappointing", "unsatisfying" or "implausible" are so murky because creativity needs that muddiness, needs to work away from the light of our attention?"
I think there's a very interesting point here which I have a personal take on influenced by my own efforts at creativity.
Consider some of the language of creativity; people are:
- Struck by a thought
- Hit by an idea
- Visited by their muse
- Inspired by...
What these have in common is the idea of something coming from the outside to aid the self. They emphasise the external orientation of creativity: the concept that the self merely 'channels' ideas and energy from somewhere else.
Of course we are all influenced by external factors. So, to a certain extent these phrases are appropriate - creativity doesn't occur in a vacuum. But for a person in the middle of creating something, it can feel like the words, images, thoughts, forms, structures, relationships, notes or rhythms are coming from elsewhere. Unfortunately taking this apparently external locus too literally can be extremely detrimental to creativity.
When I first started writing I fell for this externally oriented language of creativity hook, line and sinker. I sat down in front of the computer and waited for the muse to visit me, an idea to strike, or some other vaguely conceptualised kind of external inspiration.
It usually didn't work, I just ended up going out for a walk to get away from the empty screen and the blinking cursor, still looking for my 'inspiration'.
It's the classic rookie mistake of course. The truth is, there is no muse, there is no right frame of mind and there is no perfect moment. There is only now, here, right in front of you.
In some ways the very murkiness and inaccessibility of creativity can lead us to think the ideas must be coming from elsewhere. But I'd argue that this murkiness is really a by-product of an exceptionally complicated process. People can't explain their creativity because they don't understand it themselves, and neither does anyone else.
Nowadays my way of approaching creativity is not by waiting for inspiration to strike but simply by starting with whatever I've got right here, right now. For me creativity is all about action.
Over to you...
What do you think isabella, and everyone else?
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[Image credit: b_d_solis]
Labels: Creativity
New Study: SSRI Antidepressants 'Clinically Insignificant' For Most People
A new study published today is sure to set off another storm in the ongoing debate about the widespread prescription of antidepressants. Professor Irving Kirsch at the University of Hull and colleagues in the US and Canada report that new generation 'SSRI' antidepressants like Prozac or Seroxat mostly fall, "below the recommended criteria for clinical significance" (Kirsch et al. 2008). In other words, the most modern drugs prescribed for depression generally don't work.
The study was particularly interested in whether the drugs had different effects on people with different levels of depression. Here is what they found:
- Mild depression: not tested as mild depression is usually treated with a 'talk therapy' rather than antidepressants.
- Moderate depression: antidepressants made "virtually no difference".
- Severe depression: antidepressants had a "small and clinically insignificant" effect.
- Most severe depression: antidepressants had a significant clinical benefit - but see below...
Effectiveness limited even for severe depression
When Professor Kirsch and colleagues looked more closely at the data for those who were most severely depressed they uncovered more bad news for drug manufacturers. The antidepressant effect the drugs appeared to have, though small, was largely due to differences in the effects that the placebo had on the control group rather than better response to the drug.
Let's unpack this a little.
The placebo effect means that even when you give someone a 'fake' antidepressant they still improve a little, simply because they expect to. This effect is so powerful and reliable that to be taken seriously drug studies have to compare depressed people taking an antidepressant to a control group taking a placebo.
What Professor Kirsch and colleagues found was that while the placebo effect was present for moderately depressed people, it disappeared for those who were the most severely depressed. This meant that antidepressants weren't having any more effect on those who were more depressed, it's just that in comparison to the control group that's how it appeared. In reality what was happening was that the control group weren't responding to the placebo.
The authors, therefore, conclude that there's no point prescribing SSRI antidepressants to anyone but the most severely depressed people, unless other treatments have been tried and have failed.
Can we believe this study?
So the question is: can we believe the results? Well, the study used data from 47 clinical trials that had been submitted to the US Food and Drugs Administration (FDA). The FDA already has a rigorous set of criteria for including studies, so this suggests only quality studies were included.
The data from all these studies were then combined using a statistical technique called 'meta-analysis'. This means all the studies were collected together and analysed as though they were all one huge study. By doing this you can increase the power of the study significantly.
Like many statistical techniques, though, there is some debate about the use of meta-analyses. For example it is often argued that they lump together studies with different protocols so that effectively you end up comparing apples with oranges. Whether this sort of criticism is valid depends on the study's nitty-gritty details.
High stakes
More broadly, we have to be careful about drawing conclusions from a single piece of work. There's no doubt how high the stakes are for everyone: Professor Irving Kirsch has built a career on showing the power of the placebo effect, pharmaceutical companies have built their fortunes on studies proclaiming the benefits of SSRI antidepressants, while patients are stuck in the middle.
Despite this, the evidence does seem to be mounting up against SSRI antidepressants. Although previous studies seemed to show SSRIs were effective, recent work has suggested this might be due to a bias in the way research is reported (Turner et al., 2008). Studies which show no effect have a tendency to be 'filed' rather than being submitted for publication. This can result in a much more rosy picture being painted of a drug's effectiveness than is really the case.
Either way, considering the number of people worldwide currently taking SSRI antidepressants, we can be sure this isn't the end of the story.
» Read some of the strong reactions to the antidepressant study.
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[Image credit: selva]
References
Kirsch, I., Deacon, B. J., Huedo-Medina, T. B., Scoboria, A., Moore, T. J., & Johnson, B. T. (2008). Initial severity and antidepressant benefits: a meta-analysis of data submitted to the food and drug administration, PLoS Medicine, 5(2), e45 EP
Turner, E. H., Matthews, A. M., Linardatos, E., Tell, R. A., & Rosenthal, R. (2008). Selective publication of antidepressant trials and its influence on apparent efficacy, New England Journal of Medicine, 358(3), 252-260.
Labels: Depression
7 Sins of Memory: Complete Guide
- How quickly do we forget?
- When and how are memories warped?
- What biases act on our memory?
- Why is it sometimes impossible to forget?
"Memory itself is an internal rumour." --George Santayana
The word rumour captures an aspect of memory perfectly. When we delve backwards, moments never return in their original clarity; they return as rumours of the original event. Faces have been switched, names deleted, words edited - sometimes it's as though we weren't even there.
Psychologists have found that right from the moment an event occurs, is laid down in memory (or not), to the moment we try to retrieve it (or can't), our minds are fallible. Harvard psychologist Professor Daniel L. Schacter has classified memory's slips, ambiguities and downright lies into the 'seven sins of memory': transience, absent-mindedness, blocking, misattribution, suggestibility, bias and persistence (Schacter, 1999).
But despite these 'sins', we still get by. Memory is what makes us who we are. Practically it enables us to function in everyday life. Without it we would be lost, like those with severe amnesia who can't remember who they are or achieve even the simplest of tasks. So how can memory's fallibility be reconciled with its abilities?
This series of posts explores these sins and in turn uncovers some bizarre stories as well as shedding light on everyday occurrences. The surprise is that many sins of memory have a redeeming feature; sometimes the very sin itself is the flipside of one of memory's saintly qualities, one we couldn't do without.
For future reference, bookmark this page in del.icio.us.
- How Quickly We Forget: The Transience of Memory
- Absent-Mindedness: A Blessing in Disguise?
- On the Tip-of-the-Tongue: Blocked Memories
- How Memories are Distorted or Invented: Misattribution
- When Suggestibility is a Liability: Wrongful Convictions
- How the Consistency Bias Warps Our Personal and Political Memories
- The Persistence of Memory
» If you enjoyed this post, subscribe to PsyBlog (RSS).
[Image credit: rgusick]
References
Schacter, D. L. (1999). The seven sins of memory. Insights from psychology and cognitive neuroscience. American Psychologist, 54, 182-203.
Labels: Memory
Site News: Anonymous Commenting Disabled
The reason for this is simply so that we can talk to each other here without continually referring to 'anonymous #3' or some other clumsy form of address. Also it makes things a little more personal which I think is a bonus.
Hopefully this won't curb your commenting too much because I think this is such a valuable part of PsyBlog.
As ever, let me know what you think...
Labels: Site News
The Persistence of Memory
The last of the seven sins of memory shows that being unable to forget is a double-edged sword.
Of all Daniel L. Schacter's seven sins of memory it is the last, persistence, that is the most polarised in its effect (Schacter, 1999). While the persistence of memory can be vital to our survival, at the same time it can leave us haunted by past events we might rather forget. As in surrealist Salvador Dali's most famous painting, 'The Persistence of Memory', memories can weigh heavily on our minds; thoughts, like ants, scurrying: endlessly searching for who knows what.
Post-traumatic stress disorder
For those suffering from post-traumatic stress disorder, images and recollections of a traumatic event become an intrusive and sometimes unbearable part of everyday experience. The trauma continues to resurface, again and again, despite attempts at thought management or repression. Of course being able to repress these memories would provide some relief for sufferers, but is it possible?
Professor Richard McNally and colleagues from Harvard University wanted to find out whether memories such as these could be effectively repressed by trauma sufferers using a 'directed forgetting' procedure: essentially just telling people to forget (McNally et al., 1998).
They studied a group of 14 women who had been sexually abused as children and compared them with a control group. Participants in both groups were directly asked either to remember a particular word or to forget it. Some of the words they were asked to remember or forget were related to traumatic memories (e.g. 'abuse').
What Professor McNally and colleagues found was that control participants were more likely to forget trauma words they were told to forget, while remembering trauma words they were told to remember. It seemed control participants could successfully suppress their memories. The same could not be said of participants who had suffered traumatic experiences. These participants were unable to consciously forget words that were trauma-related. This suggests that people who have experienced a trauma lose conscious cognitive control over aspects of their memory.
It seems that the persistence of some memories is too strong for us to consciously control: suppression is not an option.
The depressive cycle
The intrusive persistence of disturbing past episodes may also be particularly important in depression. In fact this persistence can produce a dangerous cycle which may be key to the maintenance of depressive disorders. Ruminating over past events can lead to depression, while depression can then lead straight back in to rumination. It is a vicious circle.
There's evidence for this depressive cycle from studies which show two different aspects of memory's persistence.
1. Depression leads to rumination
Studies have examined the unconscious ways depressed people process their memories. Watkins et al. (1996), for example, compared depressed participants to a control group in how they responded to positive and negative words. The results showed that while the control group tended to be biased towards remembering more positive words, the depressed participants remembered more negative words.
This suggests that depressed people are more likely to remember past negative events - the first part of the depressive cycle.
2. Rumination leads to depression
To test whether rumination can feed back into depression, Lyubomirsky, Caldwell and Nolen-Hoeksema (1998) put one group of students in a ruminative mood using a simple self-focussing task. They wanted to see how these moods affected the types of memories they then recalled:
- The first group were put into a ruminative mood with an exercise which focussed attention internally. They were, for example, asked to recall and think about one of their dreams.
- The second group turned their attention outwards by, for example, thinking about the shape of clouds in the sky. This was designed as a filler task to help block self-focussed thoughts.
Participants were then asked to recall at least eight incidents that had happened to them - anything they liked. The results showed that those participants who had been put in a ruminative mood tended to recall more negative memories than those who'd been engaged in the filler task.
This experiment is evidence for the second part of the depressive cycle: that ruminative thinking leads to the recall of more negative memories. This in turn is likely to lead to depression.
Taken together these two studies, and others like them, suggest the persistence of memory can play an important role in the maintenance of depression.
Memory's persistence helps us survive
But that's enough of depression and trauma. The fact is that, of the seven sins of memory, it is easiest to see the positive, adaptive nature of memory's persistence. Our very survival relies on the fact that we remember when bad consequences follow from particular situations.
Living in a comfortable modern society may mean a person has relatively few real life-threatening dangers to face on a regular basis. But when people are exposed to more precarious environments, making the same mistake twice can be disastrous. Depression and traumatic stress disorders may partly be the regrettable downsides of memory systems that are designed to keep us alive.
This post is part of a series on the seven sins of memory:
- How Quickly We Forget: The Transience of Memory
- Absent-Mindedness: A Blessing in Disguise?
- On the Tip-of-the-Tongue: Blocked Memories
- How Memories are Distorted or Invented: Misattribution
- When Suggestibility is a Liability: Wrongful Convictions
- How the Consistency Bias Warps Our Personal and Political Memories
- » The Persistence of Memory
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[Image credit: Salvador Dali]
References
Lyubomirsky, S., Caldwell, N. D., & Nolen-Hoeksema, S. (1998). Effects of ruminative and distracting responses to depressed mood on retrieval of autobiographical memories, Journal of Personality and Social Psychology, 75(1), 166-177.
McNally, R. J., Metzger, L. J., Lasko, N. B., Clancy, S. A., & Pitman, R. K. (1998). Directed forgetting of trauma cues in adult survivors of childhood sexual abuse with and without posttraumatic stress disorder, Journal of abnormal psychology, 107(4), 596-601.
Schacter, D. L. (1999). The seven sins of memory. Insights from psychology and cognitive neuroscience. American Psychologist, 54, 182-203.
Watkins, P. C., Vache, K., Verney, S. P., Muller, S., & Mathews, A. (1996). Unconscious mood-congruent memory bias in depression., Journal of Abnormal Psychology, 105(1), 34-41.
Labels: Memory
Blind People's Other Senses Not More Acute
Mind-myth 2: studies show that the blind's other senses are not more acute, but they can learn some amazing skills to compensate, like echolocation.
It's an oft-repeated idea that blind people's other senses compensate for their lack of sight. Like the idea that we only use 10% of our brains, it is probably repeated because its rosy optimism seems harmless. In fact it's a myth with a kernel of truth.
To shoot this myth down we need to make an important distinction. There is a difference between having better hearing, and using auditory information more effectively, which some blind people do to an extraordinary degree. This difference is at the root of the myth. Let's have a look at what the studies have found.
Smelling
Studies have compared the threshold at which blind and sighted young people can identify smells. Rosenbluth, Grossman and Kaitz (2000), for example, found no difference in this, nor in blinded and sighted children's ability to identify the different smells they were exposed to. The blind children did, however, give a wider range of labels to the smells, suggesting they paid more attention to smells.
Hearing
The spatial hearing abilities of blind and sighted individuals were examined by Ashmead et al. (1998). They tested how well participants were able to tell the direction a sound was coming from. In this test the blind children did perform better, but only marginally so. Again, this suggests blind children are making better use of their sense of hearing, not that their sense of hearing is ramped up to compensate for lack of sight.
Touching
Perhaps, though, despite not having superior olfactory or auditory powers, blind children have a better sense of touch? Morrongiello et al. (1994) tested this by giving blind and (blindfolded) sighted children different types of objects to identify. Some objects were miniature versions of large objects, like a bicycle, while other objects were oversized versions of small objects, such as a big key.
In fact both groups got the same number of objects correct, had problems with the same objects and seemed to use the same strategies to identify the objects. A study on older children did, however, find evidence that by the age of 13 blind children had developed superior tactile strategies than sighted children (D'Angiulli, Kennedy & Heller, 1998).
Other senses?
Of course smelling, hearing and feeling are not the only human senses. There is also taste along with less-famous but no less vital senses like thermoception (temperature), equilibrioception (balance) and proprioception (body awareness). I haven't been able to find studies on these but I'd be willing to bet the findings would be the same as for hearing, feeling and smelling.
So strictly speaking the myth is just that, blind people's other senses don't compensate for their lack of sight. But, while blind people don't have a more acute sense of smell, taste or touch, they can use these senses more effectively.
Learning echolocation
Using echolocation is one of the most striking demonstrations of the way in which people can make more effective use of their sense of hearing. Dan Kish is the Director of World Access for the Blind and this inspiring short film explains how he uses echolocation to safely ride a bicycle on the public roads, just by clicking his tongue. This is absolutely fantastic!
» Find out if any other mind-myths catch you out.
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[Image credit: Violater3]
References
Ashmead, D. H., Wall, R. S., Ebinger, K. A., Eaton, S. B., Snook-Hill, M. M., & Yang, X. (1998). Spatial hearing in children with visual disabilities., Perception, 27(1), 105-22.
D'Angiulli, A., Kennedy, J. M., & Heller, M. A. (1998). Blind children recognizing tactile pictures respond like sighted children given guidance in exploration, Scandinavian Journal of Psychology, 39, 187-190.
Rosenbluth, R., Grossman, E. S., & Kaitz, M. (2000). Performance of early-blind and sighted children on olfactory tasks, Perception, 29(1), 101-110.
Morrongiello, B. A., Humphrey, G. K., Timney, B., Choi, J., & Rocca, P. T. (1994). Tactual object exploration and recognition in blind and sighted children., Perception, 23(7), 833-48.
Labels: Mind-Myths
How the Consistency Bias Warps Our Personal and Political Memories
What were your political views a decade ago? How good was your relationship last year? Studies show we often assume things haven't changed, when in fact they have.
New experiences don't fall on a blank slate; we don't merely record the things we see around us 'as they are' (if such a thing exists). Everything we do, have done to us, think or experience, is affected by past thoughts and things that have already happened to us. As a result we can't help but put our own personal spin on our memories. It's this 'spin' that is the sixth of Daniel L. Schacter's seven sins of memory: bias (Schacter, 1999).
One of the most fascinating biases acting on our memories is the consistency bias. This is the finding, not dissimilar to cognitive dissonance, that we will often reconstruct the past to make it more compatible with our current worldview. Studies have shown the bias operating in both our personal relationships and our political attitudes.
Political bias
Is it possible that we might re-write our attitudinal autobiographies so they fit more closely with our current position? Do we effectively lead ourselves to believe that what we think today about, say, our country's foreign policy, is what we've always thought? How have your politics changed over the last decade? Chances are that you underestimate how much your attitudes have evolved. So says a study into people's political beliefs carried out by Greg Markus from the University of Michigan (Markus, 1986).
Markus used data collected about political opinions from two generations, at two points in time, once in 1973 and then again in 1982. Eight-hundred and ninety-eight parents, along with 1,135 of their offspring provided data on their attitudes towards issues like gender equality, rights of the accused and the legalisation of marijuana.
The results showed that overall, as is often noted, both parents and their children became more conservative as they got older. But all the fun started when people were asked to think back to the beliefs they had reported almost ten years ago. On average only about a third of people correctly recalled their political positions from 1973, nine years later. The same proportion of people recalled their position incorrectly by 3 or more points on a 7 point scale. The rest were somewhere in between.
So people weren't that good. But maybe this isn't surprising: people often have considerable difficulty dredging up their current political beliefs, let along those from 9 years ago. But if people had just forgotten their previous beliefs then it seems unlikely that their guesses should be systematic in any way, and yet they were. Much more often than not, people guessed their remembered attitudes as closer to their current attitudes.
Effectively people who supported the legalisation of marijuana in 1973, but had actually changed their minds by 1982, were then more likely to say their attitude in 1973 was more anti-legalisation than it actually had been. This might help explain why people think their politics hasn't changed much over the years, when in fact the exact reverse is often true.
Markus also found that one exception to the consistency bias was when people's political opinions were more available to memory, e.g. when their feelings were strong on a particular issue. Then those opinions were more likely to be correctly recalled.
This consistency bias isn't just seen for political beliefs, though, it can also strike closer to home.
Relationship bias
Elaine Scharfe and Kim Bartholomew from Trent University and Simon Fraser University used a similar approach to the political study, but this time focussing on people's romantic relationships (Scharfe & Bartholomew, 1998). They asked people to rate the stability of their relationships at two points, 8 months apart. Then, at the second time-point they were also asked to rate how they remembered their relationships 8 months ago.
Compared to the political study, people did better with their romantic partners. The majority of people were reasonably accurate at remembering the state of their relationships from 8 months ago. This might be expected because of the shorter gap in time and because of the more personal nature of the questions.
Despite this, those who were relatively inaccurate still displayed a consistency bias. This meant that, for example, if their relationships had improved in the intervening 8 months then they tended to assume it had always been that way. It's interesting that although the consistency bias is weaker here, it's not gone altogether.
The change bias
While the consistency bias is important, sometimes our memory biases work in the exact opposite direction, and we assume more change has occurred than really has, especially if that's what we're expecting. A common example is when we're trying to learn a new skill. If we put loads of effort in to learning that new skill, we often think our improvement is much greater than it really is.
Michael Conway and Michael Ross at the University of Waterloo in Canada examined just this phenomenon in research into people's study skills (Conway & Ross, 1984). Their study relied on the fact that so-called 'study skills' courses seem to have little impact on people's academic achievement. In their experiment all the participants were first asked to evaluate their own study skills, then one group took a study skills course while the other group was assigned to a waitlist.
After three weeks both groups were asked to evaluate their study skills before the course. The group who had taken the course were more likely to evaluate themselves as worse before the course, while the waitlist control group showed no systematic biases.
Sure enough at the end of term, the study skills group did no better than the control group in the exam. Despite this, when the study skills groups were asked about their performance 6 months later, they thought they had done better than they had. Again, no systematic biases were seen in the control group.
Although this effect is often referred to as a change bias, it's really just another form of consistency bias. People are again extrapolating backwards using the changes they think ought to have (or not) occurred over that period. It just so happens that instead of assuming their political beliefs or relationship will be the same, this time they're assuming their study skills must have been worse before they started the course. Once again, people are fighting for consistency.
One bias among many
The consistency bias is only one of the many types of biases that our memories demonstrate. Here are a few more examples:
- Beneffectance: we tend to believe the past glories were the result of our actions, while past disgraces were someone else's fault.
- Reminiscence bump: the fascinating finding that we remember more events from our adolescence and early adulthood than from other periods of our lives.
- Hindsight bias: that we tend to think that we could easily have predicted past events when in fact we can't.
- Rose-tinted specs: remember how wonderful things were in the olden days? It wasn't that good, trust me, nostalgia isn't what it used to be.
And this is just a few of them, a full list would probably need its own blog.
Why memory biases are useful
Like the other so-called 'sins' of memory, the biases displayed by memory are often by-products of their central purpose. Building up cognitive maps of what we expect from the world helps us navigate through it successfully. If you've found from past experience that going to a bar and knocking people's drinks out of their hands tends to correlate with visits to the emergency room, you can learn something. The fact that these 'maps' also impinge on our recollections of past events is a small price to pay for the advantages we gain.
Some memory biases might even be directly useful to us. To take the two examples discussed here, believing that we are more consistent than we really are in our political beliefs and our relationship choices might help to boost confidence in ourselves. Similarly, believing that putting in effort leads to improved performance helps motivate us to put in effort next time as well. Factors such as these may all contribute towards our overall satisfaction with life.
So, maybe while we should be suspicious of our biases, we should ultimately be thankful for our inconsistencies.
This post is part of a series on the seven sins of memory:
- How Quickly We Forget: The Transience of Memory
- Absent-Mindedness: A Blessing in Disguise?
- On the Tip-of-the-Tongue: Blocked Memories
- How Memories are Distorted or Invented: Misattribution
- When Suggestibility is a Liability: Wrongful Convictions
- » How the Consistency Bias Warps Our Personal and Political Memories
- The Persistence of Memory
» If you enjoyed this post, subscribe to PsyBlog (RSS).
[Image credit: TeeRish]
References
Conway, M., & Ross, M. (1984). Getting what you want by revising what you had, Journal of personality and social psychology, 47(4), 738-748.
Markus, G. B. (1986). Stability and change in political attitudes: observed, recalled, and explained, Political Behavior, 8(1), 21-44.
Schacter, D. L. (1999). The seven sins of memory. Insights from psychology and cognitive neuroscience. American Psychologist, 54, 182-203.
Scharfe, E., & Bartholomew, K. (1998). Do you remember? Recollections of adult attachment patterns, Personal Relationships, 5(2), 219-234.
Labels: Memory
When Suggestibility is a Liability: Wrongful Convictions
Daniel Schacter's fifth sin of memory, suggestibility, is a close cousin of misattribution. Like misattribution it involves the creation of a false memory. But, while a misattribution is of our own making, a suggestion comes from someone else who is, whether intentionally or not, influencing us. Human suggestibility has many implications, but some of its most devastating consequences have been played out in the criminal justice system.
Criminal justice systems around the world have treated human memory with undeserved reverence for a long time. Dubious eyewitness testimony has frequently secured convictions for the most serious of crimes. Even more incredibly for students of scientific psychology, repressed memories rising to the surface decades after the original event have been accepted by courts as the basis to lock a man away for the rest of his life.
In three recent posts PsyBlog has examined experiments showing just how prone we are to suggestion. Given the right circumstances people will finger the wrong suspect in a line-up, manufacture false memories and even change their beliefs after having their dreams interpreted.
Read on about the effects of positive feedback on eyewitnesses -»
Read on about implanting false memories -»
Read on about the effect of dream interpretation on memory -»
This post is part of a series on the seven sins of memory:
- How Quickly We Forget: The Transience of Memory
- Absent-Mindedness: A Blessing in Disguise?
- On the Tip-of-the-Tongue: Blocked Memories
- How Memories are Distorted or Invented: Misattribution
- » When Suggestibility is a Liability: Wrongful Convictions
- How the Consistency Bias Warps Our Personal and Political Memories
- The Persistence of Memory
» If you enjoyed this post, subscribe to PsyBlog (RSS).
[Image credit: Dani3D]
Labels: Memory
Reader Poll: Accessibility Results
Well, 305 of you voted and here's what you said:
- 1%: Usually too complicated for me, please make it simpler!
- 5%: Sometimes too complicated, it would be better if you explained things more.
- 7%: Sometimes too complicated, but that's fine with me.
- 51%: Almost always at the right level for me.
- 24%: Sometimes too simplistic, but that's fine with me.
- 5%: Sometimes too simplistic, it would be better if you skipped the easy stuff.
- 7%: Usually too simple for me, please increase the complexity!
I'm happy to see that the majority of respondents (just!) are finding PsyBlog is at about the right level for them. But, 36% of you find, at least some of the time, that PsyBlog's content is too simplistic for you; as opposed to 13% finding it too complex. Overall, then, your message as a group seems to be that including a little more complexity wouldn't hurt. I'm mindful, though, of not excluding readers.
It's worth pointing out that this poll is exactly what you would expect since the complexity of the content will tend to attract people who are happy at, or around, that level. And so we go around in a circle...
Still, it's nice to see you arrange yourselves into a fair approximation of a bell-curve type normal distribution. Well done!
[Image credit: Lumaxart]
Labels: Site News
Therapists Can Implant False Beliefs and Memories
Studies have shown that false memories can be implanted under experimental conditions, so is it possible for therapists to change their clients' beliefs or memories through suggestion? An experiment by Giuliana Mazzoni from the University of Florence and colleagues demonstrates the power psychotherapists potentially wield with a mere 30 minute interpretation of a dream (Mazzoni et al., 1999).
This intriguing experiment had three stages:
- Participants' very early childhood memories were tested.
- Dream interpretation was used to implant a false childhood event that was mildly traumatic.
- Participants' memories were tested again for their belief in the implanted event and whether they had constructed any memories associated with it.
This is how it worked:
Part 1: Early childhood memories
One-hundred and fifty-nine potential participants were first asked to fill out a questionnaire asking about events they remembered occurring to them before the age of 3. The questionnaire asked how confident they were in each of these memories. The events included things like 'found some lost keys' or 'hand caught in mousetrap', but there were two questions experimenters were particularly interested in: 'was harassed by a bully' and 'was lost in a public place for more than one hour'. Only the 72 who were reasonably confident this event hadn't happened to them were selected for the experiment.
These participants were then randomly split into two groups, with one acting as a control group while the other group were targeted with a dream interpretation session designed to change their beliefs and memories.
Part 2: Dream interpretation
Around two weeks, later the dream interpretation group were invited to take part in another study which appeared unrelated to the earlier questionnaire they had filled out. They were told it was a 'Dream and Cognition Study', where they would bring two of their dreams to a session with an expert in dream interpretation. In fact the expert dream interpreters were the experimenters.
When participants arrived at the session they were introduced to a 'clinical psychologist' who would interpret their dreams. But the clinical psychologist, over a 30 minute session, instead of interpreting all the different dreams brought to her in different ways, rather single-mindedly gave one specific interpretation to all the different dreams. Every participant was ultimately told that their dream probably indicated they had been bullied as a child or lost in a public space depending on which question they had answered 'no' to in the earlier questionnaire. It was also suggested this had probably happened before the age of 3.
Participants in the control group did not take part in this section of the study.
Part 3: Checking memories again
A further couple of weeks later all the participants were called back to fill in exactly the same questionnaire they had completed in part 1. They were told that this study was assessing the reliability of the scale asking about early events, which is ironic because it was really testing the reliability of their memories.
Result: Confidence in false memory increased
Impressively, fully half of the dream interpretation group reported increased confidence in their belief that they were either lost in a mall or had been bullied by an older child before the age of 3. Of these people, half produced concrete reports of the events having occurred. They actually built on the dream interpretation to fabricate memories of their own. This was despite previously being fairly certain these events had never occurred.
In the control group, however, only a few people increased their confidence the childhood event had occurred. In addition, 30% of the control group actually reported decreased confidence they had been bullied or were lost as a child compared to only a few percent of the dream interpretation group. This suggests the dream interpretation group hadn't simply had their memories jogged.
Also, suggestibility varied significantly between people. In this study those who believed in the power of dream interpretation were more likely to change their beliefs and generate false memories.
Therapist power
Despite these impressive results, this experiment probably under-estimates the power therapists could potentially wield over their clients' beliefs and memories. The experiment examined only people visiting a 'clinical psychologist' who they had never met before and about whom they probably had few expectations, other than that they were apparently a dream expert.
Real clients visiting their real therapist are probably much more invested in the relationship and hence probably much more open to suggestion. Hopefully, of course, the strength of the therapeutic relationship can be used to make positive changes, but it is worth remembering that there are two sides to the coin.
This post is part of a series on the seven sins of memory:
- How Quickly We Forget: The Transience of Memory
- Absent-Mindedness: A Blessing in Disguise?
- On the Tip-of-the-Tongue: Blocked Memories
- How Memories are Distorted or Invented: Misattribution
- When Suggestibility is a Liability: Wrongful Convictions
- Wrongful Conviction: 50% of Mistaken Eyewitnesses Certain After Positive Feedback
- Implanting False Memories: Lost in the Mall & Paul Ingram
- » Therapists Can Implant False Beliefs and Memories
- How the Consistency Bias Warps Our Personal and Political Memories
- The Persistence of Memory
» If you enjoyed this post, subscribe to PsyBlog (RSS).
[Image credit: BillyWarhol]
References
Mazzoni, G. A. L., Loftus, E. F., Seitz, A., & Lynn, S. J. (1999). Changing beliefs and memories through dream interpretation., Applied Cognitive Psychology, 13(2), 125-144.
Labels: Memory
Implanting False Memories: Lost in the Mall & Paul Ingram
In 1990 George Franklin became the first ever US citizen convicted of murder by a witness who recovered repressed memories more than 20 years after the event. The fact that the witness was Franklin's daughter, Eileen, ensured the case was splashed across the news media. Franklin was released in 1996 after 6 years in prison when irregularities were discovered in Eileen's evidence: it emerged she had been hypnotised before testifying.
There is a good reason why hypnotised witnesses are barred from testifying in some jurisdictions: under hypnosis people are highly suggestible. Even without hypnosis, studies show that people's memories are open to influence. But, can it be demonstrated in the lab that memories for entirely false events can be implanted?
False memories are hard to research for one simple reason: it's difficult to verify whether the memories in question are false or not (Loftus, 1993). Often a considerable amount of time has passed since the original event and it's not possible to corroborate what people say. But, while it's difficult, it's not impossible - it just takes some concerted effort.
Lost in the mall
Elizabeth Loftus, Distinguished Professor at the University of California, Irvine, has been at the forefront of psychological research into repressed memories and testified in George Franklin's case. She has also carried out some fascinating research into the possibility of implanting false memories.
In a seminal study Loftus and Pickrell (1995) recruited 24 participants who were to be presented with four stories from when they were between 4 and 6 years old, three of which were true, and one false. To get the true stories, the researchers spoke to participants' relatives to get three events for each person which had really happened. The events were chosen so that they were not traumatic or emotionally difficult to recall.
Each family was also asked to provide the circumstances of another event that could possibly have happened, but didn't. In each case the false memory was for getting lost in a shopping mall. Relatives provided details of a specific shopping mall it could have been along with other details to make the fake story plausible. They also confirmed that an event like this had not actually occurred.
Do you remember this?
Participants themselves were told they were involved in a study about their ability to recall details of childhood memories. Each participant was first sent a written description of the four events their relatives had outlined - three being real and one fake. They were then asked to write down which events they remembered and more details of the events those events.
Then, soon after, participants were interviewed. At this point they were reminded about the four memories and asked to recall as much as they could about them. At a second interview a week later, a similar procedure was followed. At the end of both interviews participants rated the clarity of their memories.
It was then revealed to them that one of the memories was false and they were asked to guess which one it was. Of the 24 participants, 5 falsely recalled the made up 'lost in the mall' event as a real memory, although participants understandably found the implanted memory much less clear.
This may seem like quite an unimpressive proportion, but considering the very low level of suggestion or coercion involved in the interviews, it does at least show the possibility of implanting false memories.
A later study with more participants which examined a wider range of memories was carried out by Hyman and Pentland (1996). This found that, depending on experimental variables, at least some kind of false memory could be implanted in between 20% and 40% of participants.
But psychologists have done better. In a fantastically titled paper, 'A picture is worth a thousand lies', Kimbereley Wade and colleagues used a doctored photograph of a fictitious balloon flight to implant false memories (Wade, Garry, Read & Lindsay, 2002). Using similar interview procedures to Loftus and Pickrell (1995), they found that 50% of participants created either complete or partial false memories of the flight.
The bizarre case of Paul Ingram
Critics argue that the problem with these sorts of studies is that they only implant inconsequential memories. Traumatic memories, such as those claimed by George Franklin's daughter, might be a completely different matter. This is a fair point and difficult to refute because it would be highly unethical to implant traumatic memories into participants.
Well, actually this has been done, in one of the most bizarre and dramatic false memory experiments ever documented.
In 1988 Paul Ingram, a police officer, was arrested for sexually abusing his two daughters, an allegation he strongly denied. Over an extended period of five months, however, he was subjected to pressure by fellow police officers, psychologists and other advisors, suggesting he had committed child abuse, including having raped his own daughters.
Eventually Ingram began to confess to all manner of rapes, child sexual abuses and even to participation in a Satan-worshipping cult which had allegedly murdered 25 babies.
At one point the prosecution brought in the renowned memory researcher, Dr Richard Ofshe, now Professor Emeritus at the University of California, Berkeley. He was asked to interview Ingram. Ofshe soon became suspicious of Ingram's credibility. In order to test Ingram, he made up a story that his son and daughter claimed he had forced them to have sex with each other while he watched. This was something Ofshe confirmed with both son and daughter had not actually happened.
Over a period of hours, and despite initially denying the memory, Ingram slowly began to generate these false memories. Ultimately Ingram wrote a three-page confession to a crime that was completely fabricated. What else might he have fabricated under this kind of intense pressure?
Unfortunately for Paul Ingram, Ofshe's report wasn't issued until after he had already confessed to the crimes and been convicted. He was then unable to withdraw his guilty plea. Paul Ingram remained in jail until 2003 and is still a registered sex offender despite many doubting his guilt.
--
The case of Paul Ingram along with the experimental studies on false memories probably represent two extremes of a continuum. At one end, when politely asked within the context of a psychology study, some people can be induced into believing relatively benign false memories. Perhaps as many as 50%. At the other end, when placed under incredible psychological pressure, like Paul Ingram, who knows what people will claim to remember.
This post is part of a series on the seven sins of memory:
- How Quickly We Forget: The Transience of Memory
- Absent-Mindedness: A Blessing in Disguise?
- On the Tip-of-the-Tongue: Blocked Memories
- How Memories are Distorted or Invented: Misattribution
- When Suggestibility is a Liability: Wrongful Convictions
- Wrongful Conviction: 50% of Mistaken Eyewitnesses Certain After Positive Feedback
- » Implanting False Memories: Lost in the Mall & Paul Ingram
- Therapists Can Implant False Beliefs and Memories
- How the Consistency Bias Warps Our Personal and Political Memories
- The Persistence of Memory
» If you enjoyed this post, subscribe to PsyBlog (RSS).
[Image credit: michaelrighi]
References
Hyman, I. E., Jr., & Pentland, J. (1996). The role of mental imagery in the creation of false childhood memories. Journal of Memory and Language, 35, 101-117.
Loftus, E. F. (1993). The reality of repressed memories. American Psychologist, 48, 518-537.
Loftus, E. F., & Pickrell, J. E. (1995). The formation of false memories. Psychiatric Annals, 25, 720-725.
Wade, K. A., Garry, M., Read, J. D., & Lindsay, D. S. (2002). A picture is worth a thousand lies: using false photographs to create false childhood memories, Psychonomic Bulletin & Review, 9(3), 597-603.
Labels: Memory
Seriously, Would You Admit to Only Using 10% of Your Brain?
Mind-myth 1: Like many of the myths now seemingly fuelled by New Agers hoping to unlock the untapped, hidden forces that will unleash previously unimagined human potential, the 10% myth is a slippery customer.
Just when all the evidence has been marshalled against its original incarnation, showing that, yes, actually we do physically use all our brains, it turns out 'human potential' can't be measured empirically. Apparently the unused 90% is hidden below the surface, out of sight and almost out of mind. Which is convenient.
Let's start at the start.
The idea that we only use 10% of our brains is probably such an enduring myth because it's comforting to think we have spare capacity. The 'unused' 90% could take up the slack after brain injury or offer the possibility for miraculous self-improvement. This flexible factoid has been used not only to sell products to enhance our brain's performance, but also by psychics like Yuri Geller to explain mystical cutlery bending powers.
Boring, tedious, but unavoidable facts
Unfortunately there's four good reasons it's almost certainly false (Beyerstein, 1999):
- If we only use 10% of our brains then damage to some parts of our brains should have no effect on us. As any neurologist will tell you, this is patently not true.
- From an evolutionary perspective it is highly unlikely we developed a resource-guzzling organ, of which we only use 10%.
- Brain imaging such as CAT, PET and fMRI shows that even while asleep there aren't any areas of our brain that completely 'switch off'.
- Parts of the body that aren't used soon shrivel and die. Same goes for the brain. Any neurons we weren't using would soon shrivel and die.
The structure of the brain and its metabolic processes have also been carefully examined, along with the diseases that afflict it. None of this work has suggested there is a hidden 90% that we're not using. Unfortunately.
Anyone who still maintains we only use 10% of our brains after this fusillade of fact has to come up with a counter-argument for each one of these. Actually, you might argue that imaging technology is rubbish or the neurons are only working at 10% capacity, but refuting all four, taken together? Now that's tricky.
Mythical roots
The roots of this myth are very difficult to discern, probably because there are so many different, diffuse stories about its origin. One probably apocryphal story is that Einstein once explained his brilliance - compared to the rest of us mere mortals - by saying he actually used more than 10% of his brain (Wanjek, 2003). Despite probably being based on a misquote, the repeating of this story can't have hurt the myth's power.
Perhaps some of the earliest roots of the myth come from work by physiologists in the 1870s. They routinely applied electrical currents to the brain to see which muscles moved. They found that large parts of the human brain could be zapped without any corresponding bodily twitching. This led them to dub parts of the brain 'silent'. But they didn't mean silent in the sense of inactive, just that it didn't make any muscles move. Of course this didn't stop the phrase being misinterpreted.
The actual confirmed first written sightings of this myth, though, is in a 1940s advert for the book Cold Comfort Farm by Stella Gibbons (Wanjek, 2003, p.21):
"What's holding you back? Just one fact -- one scientific fact. That is all. Because, as Science says, you are using only one-tenth of your real brain-power!"
Whatever its provenance, the 10% myth is certainly a slippery customer. The reason is two-pronged: first, it's impossible to prove something doesn't exist and second, people like to believe it. If I say I've seen a Pegasus, or visited Mars, or that all our brains have huge untapped potential, you can't definitively prove me wrong. That's why, despite a few good solid blows to the head, this myth refuses to go down.
Perhaps putting it the other way around might deliver the knock-out blow. Instead of talking about the 90% of untapped potential, just ask people why they only use 10% of their brains. Would anyone seriously admit to that? I, for one, am working at maximum capacity. Well, most of the time anyway...
» Find out if any other mind-myths catch you out.
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[Image credit: Clint M Chilcott]
References
Beyerstein, B. L. (1999). Pseudoscience and the brain: tuners and tonics for aspiring superhumans. In: S. Della Sala (Ed.). Mind myths: Exploring popular assumptions about the mind and brain. London: John Wiley & Sons.
Wanjek, C. (2003). Bad medicine: misconceptions and misuses revealed, from distance healing to vitamin o. London: John Wiley & Sons.
Labels: Mind-Myths
Reader Poll: Is PsyBlog Accessible to You?
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Labels: Site News
When Cognitive Dissonance Doesn't Matter
Although cognitive dissonance is a powerful, well-known predictor of human thought and behaviour, its limits are less well understood.
People often display a striking ability to change both their behaviour and their view of the world to try and make it self-consistent. For example, people will interpret seemingly inconsistent information to support their own view of the world and they will adjust their attitudes to make it consistent with their behaviour. One example is that people often value a club or society more if it is harder to get into, even if it turns out to be rubbish.
Psychologists have labelled the cause of this drive towards self-consistency 'cognitive dissonance'. In the classic experiment on cognitive dissonance conducted in the late 1950s experimenters discovered that people will work extraordinarily hard to present a consistent front to the world.
Perhaps because of the bewildering contrariness people sometimes display, it has become one of the most heavily researched concepts in social psychology. But since the original discovery of cognitive dissonance researchers have probed its boundaries. A frequent worry has been to explain why, if the theory is correct, we are not more consistent. After all, people will frequently display major inconsistencies in their thoughts and behaviour without appearing to suffer any crippling cognitive dissonance.
People will happily explain their reasons for buying a particular dress, choosing a Mexican restaurant for their birthday party or moving lock and stock to Spain. Then, two weeks later, they will cheerfully tell you the exact opposite without any obvious compunction. Surely cognitive dissonance shouldn't allow this?
Avoiding bad consequences
One explanation for this apparent breach of cognitive dissonance lies in an experiment conducted by Cooper and Worchel (1970). The setup for this experiment was a variation on that carried out by Festinger and Carlsmith (1959). Essentially participants in that experiment were asked to dupe another person who is in on the experiment (a confederate) into thinking a particular task they are about to do is really interesting. In fact it was very boring.
Strangely, as cognitive dissonance predicts, people changed their own attitudes to the task when they were only paid a nominal fee for the experiment, but didn't when they were handsomely rewarded. It seems people are looking for a reason to lie - if money isn't the reason then it must be because the task is interesting (although it clearly isn't), so they change their attitude to be consistent with their behaviour: "I didn't lie, the task was actually interesting."
In Cooper and Worchel's (1970) study, though, another variation was introduced. When the participant explains to the confederate that the task is really interesting, the confederate has been told to react in one of two ways. In the first condition they act convinced by what the participant has told them; in the other condition they appear unconvinced.
This is designed to test the idea that cognitive dissonance only operates when people think their inconsistent behaviour has had some bad consequence that they would rather avoid. In this case it's the nasty feeling in one condition that the participant has lied to someone, and they believed it.
Sure enough, when the confederate acts convinced and the participant believes they've 'been bad', they change their attitude towards the boring task - then claiming it is more interesting. In the other condition, however, cognitive dissonance didn't operate. Participants who had interacted with the confederate who remained unconvinced didn't change their attitude towards the task itself. They still thought it was boring - as it surely was. It seemed they felt no need to change their attitude to the task because their lie didn't have any consequences they wanted to avoid.
Foreseeing the problem
It's not just consequences that we'd rather avoid that activates cognitive dissonance, though, these consequences must also be foreseeable. This is demonstrated in a study by Goethals, Cooper and Naficy (1979) in which participants were asked to write an essay which was designed to be in direct opposition to their own attitudes towards an on-campus policy. Participants were split into three groups:
- This group had been told only the experimenter would look at the essay.
- This group had been told that their essays would be sent to a university committee who would implement the unwanted policy.
- This group had been told their essays might be forwarded.
After the experiment all the participants were told their essays would be forwarded to the university committee. True to form participants in both groups 2 and 3 later changed their attitude towards the on-campus policy.
Participants in group 1, however, who had no way of knowing their essays would be forwarded to the relevant authorities, maintained the same attitude towards the policy. It seemed that cognitive dissonance did not operate when the bad consequences were unforeseeable.
Limits of cognitive dissonance
These limits on cognitive dissonance, that consequences must be both aversive and foreseeable, make the theory considerably more realistic. It helps to explain why people in many situations are happy to change their behaviours or attitudes in an inconsistent manner. In everyday life we are happy to admit to our own inconsistencies right up until the point where it actually matters, and we can see it's going to matter.
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[Image credit: B Tal]
References
Cooper, J. (2007). Cognitive dissonance: fifty years of a classic theory. London: Sage.
Cooper, J., & Worchel, S. (1970). Role of undesired consequences in arousing cognitive dissonance., Journal of Personality and Social Psychology, 16, 1-13.
Goethals, G. R., Cooper, J. & Naficy, A. (1979). Role of foreseen, foreseeable, and unforeseeable behavioral consequences in the arousal of cognitive dissonance., Journal of Personality and Social Psychology, 37(7), 1179-85.
Festinger, L., & Carlsmith, J. (1959). Cognitive consequences of forced compliance. Journal of Abnormal Psychology, 58, 203-10.
Wrongful Conviction: 50% of Mistaken Eyewitnesses Certain After Positive Feedback
This study dramatically illustrates one of the seven sins of memory: suggestibility.
Faulty eyewitness testimony is one of the leading causes of wrongful convictions in the US. On the basis of mounting evidence, psychologists have argued that a major contributing factor to these wrongful convictions is one of the seven sins of memory: suggestibility (Schacter, 1999).
Dramatic evidence for how easily eyewitnesses are swayed comes from a study carried out by Gary Wells and Amy Bradfield at Iowa State University (Wells & Bradfield, 1998). Like many of the best studies it is deceptively simple, but its implications for the criminal justice system are profound.
Spot the gunman
Participants were asked to watch 8 seconds of grainy security camera footage showing a man walking into a store. The footage was slowed down so that participants could get as much information as possible. The quality of the video, however, was not that good.
After watching the video, participants were told that the man is a murderer. Just after the footage cuts away, the man shot and killed the store's security guard. This information is not misleading - the CCTV footage is real - as is the subsequent murder of the security guard.
Participants were then told that their job is to identify the killer from a five-person photospread. This photospread was identical to the one used in the real case except - and here's the twist - the real gunman has been removed. Having been told, though, that the gunman is in the photospread, all the participants identify one of the men.
This is where the experimenters got clever. They then introduced three different experimental manipulations:
- One group of participants were given no feedback on their choice of suspect.
- The second were told they had made the wrong choice from the photospread and that the answer was one of the other men.
- The third group, though, were congratulated: "Good, you identified the actual suspect." Although, of course, they hadn't - no one had.
After this participants were asked about many aspects of their identification including how certain they were, how good their view of the gunman was and their ability to make out the details of his face.
That's him, I'm sure!
The results showed that simply congratulating participants on choosing the right suspect had a huge effect on their reports when compared to those told nothing and those told they were wrong. Those given positive feedback were suddenly much more sure they were right, thought the identification was easier, had a better view, thought their judgement was more trustworthy and would be more willing to testify.
Those given positive feedback even placed more confidence in their own ability to identify the gunman.
Remember that everyone is providing these reports based on exactly the same piece of store camera footage. Also, remember that everyone is wrong because the real gunman has been removed from the photospread!
The surprising thing about this experiment is what a massive effect a simple statement had on such a wide variety of factors. Giving positive (although incorrect) feedback to participants catapulted their confidence in their identifications much higher than they would have been otherwise.
On a 7-point scale only 15% of the eyewitnesses who were given negative feedback rated their confidence in their identification at either a 6 or a 7. Compare this with the eyewitnesses given positive feedback - 50% rated their confidence at either a 6 or a 7.
Participants given positive feedback even thought the security camera footage was clearer. 47% rated it at a 6 or 7 out of 7, compared with none of the eyewitnesses given negative feedback.
In a second part of the study, the authors wanted to see whether people have any idea that the feedback they receive affects their confidence in identifying the gunman. Despite the fact that it did have a substantial measurable effect, people denied the feedback had any influence whatsoever.
If you followed my series on the hidden workings of the mind, this finding won't be a surprise.
Feedback to eyewitnesses is still routine
Given the huge effect that feedback can have on confidence, clearly eyewitnesses should not be told whether they have identified the suspect or not. Wells and Bradfield (1998) point out that even when witnesses are not given verbal feedback, it is virtually impossible for police officers to avoid information leaking out through body language.
The solution suggested by Wells and Bradfield (1998) is that those administering the photospreads to eyewitnesses should be blind to the real suspect. A statement should then be taken before eyewitnesses discover whether they have picked the suspect, and their judgement is affected. Although they may subsequently inflate their claim, at least this can be compared with their original statement.
Incredibly, ten years later, it is still routine practice in the US and UK for many police forces to provide positive feedback to witnesses. This is perhaps unsurprising given the police's interest in securing convictions. Positive feedback will almost certainly bolster witnesses' confidence, thereby improving the impression they make in court.
Moves to reform police procedures in the US have foundered despite the repeated confirmation of this study's findings. Similar moves are afoot in the UK, but changes have only so far been made in some police forces.
This post is part of a series on the seven sins of memory:
- How Quickly We Forget: The Transience of Memory
- Absent-Mindedness: A Blessing in Disguise?
- On the Tip-of-the-Tongue: Blocked Memories
- How Memories are Distorted or Invented: Misattribution
- When Suggestibility is a Liability: Wrongful Convictions
- » Wrongful Conviction: 50% of Mistaken Eyewitnesses Certain After Positive Feedback
- Implanting False Memories: Lost in the Mall & Paul Ingram
- Therapists Can Implant False Beliefs and Memories
- How the Consistency Bias Warps Our Personal and Political Memories
- The Persistence of Memory
» If you enjoyed this post, subscribe to PsyBlog (RSS).
[Image credit: Bombadier]
References
Schacter, D. L. (1999). The seven sins of memory. Insights from psychology and cognitive neuroscience. American Psychologist, 54, 182-203.
Wells, G. L., & Bradfield, A. L. (1998). Good, you identified the suspect: Feedback to eyewitnesses distorts their reports of the witnessing experience. Journal of Applied Psychology, 83, 360-376.
Labels: Memory
How Memories are Distorted and Invented: Misattribution
"Most people, probably, are in doubt about certain matters ascribed to their past. They may have seen them, may have said them, done them, or they may only have dreamed or imagined they did so." --William James
One evening in 1975 an unsuspecting Australian psychologist, Donald M. Thomson, walked into a television studio to discuss the psychology of eyewitness testimony. Little did he know that at the very moment he was discussing how people can best remember the faces of criminals, there was someone encoding his own face as a rapist.
The day after the television broadcast Thomson was picked up by local police. He was told that last night a woman was raped and left unconscious in her apartment. She had named Thomson as her attacker.
Thomson was shocked, but had a watertight alibi. He had been on television at the time of the attack and in the presence of the assistant commissioner of police.
It seemed that the victim had been watching Thomson on television just prior to being attacked. She had then confused his face with that of her attacker. That a psychologist talking about identifying the faces of criminals should be the subject of just such a gross memory failure - and at the very moment he was publicly explaining it - is an irony hard to ignore.
Donald Thompson was completely exonerated but many others have not been so lucky. Gary Wells at Iowa State University and colleagues have identified 40 different US miscarriages of justice that have relied on eye-witness testimony (Wells et al., 1998). Many of these falsely convicted people served many years in prison, some even facing death sentences.
Donald Thomson's ordeal, though, is a perfect example of Harvard psychologist Daniel L. Schacter's fourth sin of memory (Schacter, 1999). Unlike the first three sins, which all involve being unable to access memories, this is the first sin that involves the creation of memories that are false in some way. When a memory is 'misattributed' some original true aspect of a memory becomes distorted through time, space or circumstances.
Daily misattributions
While misattributions can have disastrous consequences, most are not so dramatic in everyday circumstances. Like the other sins of memory, misattributions are probably a daily occurrence for most people. Some examples that have been studied in the lab are:
- Misattributing the source of memories. People regularly say they read something in the newspaper, when actually a friend told them or they saw it in an advert. In one study participants with 'normal' memories regularly made the mistake of thinking they had acquired a trivial fact from a newspaper, when actually the experimenters had supplied it (Schacter, Harbluk, & McLachlan, 1984).
- Misattributing a face to the wrong context. This is exactly what happened to Donald Thomson. Studies have shown that memories can become blended together, so that faces and circumstances are merged.
- Misattributing an imagined event to reality. A neat experiment by Goff and Roediger (1998) demonstrates how easily our memory can transform fantasy into reality. Participants were asked either to imagine performing an action or actually asked to perform it, e.g. breaking a toothpick. Sometime later they went through the same process again. Then, later still they were asked whether they had performed that action or just imagined it. Those who imagined the actions more frequently the second time were more likely to think they'd actually performed the actions the first time.
Unintentional plagiarism
So far we've seen how easily people move around the events, faces and sources of their memories. Each of these are situations where people are retrieving a real memory, but mistaking one or more of its aspects. Schacter (1999), however, points to another common type of misattribution: when we attribute an idea or memory to ourselves that really belongs to someone else.
Unintentional plagiarism has been examined in a number of studies. In one straightforward early study people were asked to generate examples of particular categories of items, like species of birds. It was found that people, without realising, plagiarised each other about 4% of the time (Brown & Murphy, 1989). Subsequent studies using more naturalistic procedures have found much higher rates using different types of tasks - sometimes as much as 27%.
That's a very high rate and probably helps to explain why we see so much unintentional repetition across many different areas of human culture. Musicians, writers and artists of all stripes have to work extremely hard to avoid unintentionally plagiarising each other.
If a song that has been unintentionally plagiarised becomes a hit, it can easily end up making the lawyers a lot of money. When George Harrison was sued for (unintentionally) plagiarising a Chiffons' hit "He's So Fine", a claim that started in 1971 dragged on until the 1990s!
All made up
Although memories often have some basis in reality, whether we've mixed up some details or even the memory's source, sometimes they are just completely false. During the 1960s and 70s psychologists discovered a way of reproducing this false memory effect in the lab.
In the classic study conducted by James Deese at Johns Hopkins University, participants are given lists of semantically related words (Deese, 1959). For example: red, green, brown and blue. Later they have to try and recall them, at which point they often recall related words that were not actually presented, like purple or black.
Later studies have replicated this finding using more complicat