Early Life Stress Has A Lasting Impact On The Brain

Toxic early life stress may critically affect memory, learning and the way emotions are processed.

Toxic early life stress may critically affect memory, learning and the way emotions are processed.

Chronic early life stress — like that from abuse, neglect or poverty — can have a lasting impact on the developing brain, according to research.

Toxic stress at an early age may critically affect memory, learning and the way emotions are processed, finds a study published in the journal Biological Psychiatry.

The research investigated exactly why early life stress can lead to such a wide range of negative outcomes later in life, including depression, anxiety, poor educational achievement and also physical problems (Hanson et al., 2014).

Seth Pollak, co-leader of the study, said:

“We haven’t really understood why things that happen when you’re 2, 3, 4 years old stay with you and have a lasting impact.

Given how costly these early stressful experiences are for society…unless we understand what part of the brain is affected, we won’t be able to tailor something to do about it.”

Study of early life stress

The researchers recruited 128 children at around the age of 12 who had experienced neglect, abuse or other serious, chronic stressors in the first few years of their lives.

The children and their caregivers were interviewed about their early life experiences and any behavioural problems they now had.

Their brains were also scanned, with a special focus on the hippocampus and amygdala, both of which are heavily involved in how the brain processes emotions.

The results from these children were compared with other children from middle-class backgrounds who had not been maltreated.

What emerged was that those who had suffered chronic stress in early life had smaller amygdalas than those who had not.

In addition, those who were from very poor backgrounds or who had been physically abused also had smaller hippocampi.

While the implications of the reduced size of the amygdala is unknown, a smaller hippocampus is a recognised risk factor for negative outcomes.

Unsurprisingly the children who’d suffered early life stress also had more behavioural problems, and the smaller the affected brain structures were, the greater the behavioural problems.

Seth Pollak said:

“For me, it’s an important reminder that as a society we need to attend to the types of experiences children are having.

We are shaping the people these individuals will become.”


1 in 5 Children Experience Something Worse Than Parental Abuse (M)

The severe effect on adult mental health of an experience suffered by one in five children.

The severe effect on adult mental health of an experience suffered by one in five children.

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Piaget Stages Of Development Theory

Piaget’s theory of four stages of development has the dubious claim to fame of being one of the most criticised psychological theories ever.

Piaget’s theory of four stages of development has the dubious claim to fame of being one of the most criticised psychological theories ever.

Jean Piaget was a developmental psychologist whose four-stage theory, published in 1936, has proved extremely influential.

From the sensorimotor stage, through the pre-operational stage, the concrete operational stage and the formal operational stage, his theory attempts to describe how childhood development progresses.

However, Piaget’s experiments and theories about how children build up their knowledge of the world have faced endless challenges, many of them justified.

Let me give you a flavour of why Piaget’s research on stages of development has faced so much criticism and also why psychologists often regard him with such awe.

First I’ll describe one of the observations he made of his own three children, then why his conclusions are probably wrong and  finally the central insight at the heart of his four-stage theory of cognitive development.

Piaget’s research on his daughter

One of Piaget’s many careful observations was made when one of his daughters, Jacqueline, then 7 months old, dropped a plastic duck on the quilt and it fell behind a fold so that she couldn’t see it.

Piaget noticed that despite the fact that Jacqueline could clearly see where the duck had dropped, and it was within her reach, she made no attempt to grab for it.

Fascinated by this, Piaget put the duck in her view again but, then, just as she was about to reach for it, he slowly and clearly hid it under the sheet.

Again, she acted as though the duck had simply disappeared, making no attempt to search for it under the sheet.

This seemed strange behaviour to Piaget as Jacqueline was clearly interested in the duck while she could see it, but seemed to forget about it the instant it disappeared from view – out of sight and, apparently, out of mind.

What Piaget deduced from these observations, along with many experiments, was that children do not initially understand the idea that objects continue to exist even when out of sight (this is known as object permanence).

This concept, he thought, children had to work out by themselves by interacting with and experiencing the world.

It wasn’t until around 9 or 10 months of age that Piaget noticed his children began to search for a hidden object.

Piaget’s four-stage theory of development

While many parents play games with their children like this, what set Piaget apart was that he used these observations along with many experiments to develop a theory of how children acquire knowledge, the stages of development theory for which he is rightly best-remembered.

This theory is a four-stage ladder up which Piaget thought children climbed as they gathered knowledge about the world (Piaget, 1936).

1. Sensorimotor stage (birth to 18-24 months)

At the first of Piaget’s stages of development, the sensorimotor stage, infants are aware only of their sensations, fascinated by all the strange new experiences their bodies are having.

They are like little scientists exploring the world by shouting at, listening to, banging and tasting everything.

2. Pre-operational stage (18-24 months to 7 years)

At the second of Piaget’s stages of development, the pre-operational stage, children can process images, words and concepts but they can’t do anything with them, they can’t yet operate on them.

It’s like they’ve acquired the tools of thought, but don’t yet know how to use them.

E.g. in maths they can’t understand that 2 x 3 is the same as 3 x 2.

3. Concrete operational stage (7 to 12 years)

At the third of Piaget’s stages of development, the concrete operational stage, children gain the ability to manipulate symbols and objects, but only if they are concrete – abstract operations are still a challenge.

4. Formal operational stage (12 and up)

At the fourth of Piaget’s stages of development, the formal operational stage, children are able to think in abstract terms about the world.

Now they can understand concepts such as the future, values and justice.

From around this age children start thinking like adults.

Criticism of Piaget stages of development theory

It’s for this grand stages of development theory that Piaget is much admired.

Unfortunately, like many an ambitious theory, over time evidence was uncovered that contradicted aspects of this neat time-line.

For example, Piaget’s conclusions about his daughter Jacqueline’s failure to reach for the duck were probably wrong.

Subsequent studies have revealed infants as young as 3.5 months appear to understand object permanence.

Psychologists nowadays might explain Jacqueline’s behaviour as a failure of memory or an inability to grasp something that is out of view.

Einstein though Piaget was a genius

Although findings such as these have chipped away at Piaget’s stages of development theory, his work has continued to attract interest and stimulate research.

From observations like hiding his daughter’s duck to his grand four-stage theory of development, Piaget’s central insight was that children think in a fundamentally different way from adults.

They don’t just have less knowledge, less experience or less processing power; the qualitative content of their thoughts is actually different.

Even though psychologists now question many of the details of Piaget’s observations and theories, this central insight remains intact.

And it’s this central insight that Albert Einstein once described as “so simple that only a genius could have thought of it”.

→ This article is part of a series on 10 crucial developmental psychology studies:

  1. When infant memory develops
  2. How self-concept emerges in infants
  3. How children learn new concepts
  4. The importance of attachment styles
  5. When infants learn to imitate others
  6. Theory of mind reveals the social world
  7. Understanding object permanence
  8. How infants learn their first word
  9. The six types of play
  10. Piaget’s stages of development theory


Attachment Styles: Secure, Avoidant, Anxious And Ambivalent

Attachment styles are important because we are social animals, relying heavily on our ability to form relationships with others.

Attachment styles are important because we are social animals, relying heavily on our ability to form relationships with others.

Attachment styles analyse how people respond to threats and problems in their personal relationships.

People who find relationships difficult often become unable to participate in the ordinary give-and-take of everyday life.

They may become hostile towards others, have problems in education as well as a greater chance of developing psychiatric disorders later in life.

These difficulties sometimes have their roots in the most important early relationships, evidenced in attachment styles.

It’s no wonder that child psychologists are so interested in the first relationships we build with our primary caregivers.

These attachment styles are likely to prove a vital influence on all our future relationships, including those with our spouse, our workmates and our own children.

While you can’t blame everything on your parents, early relationship attachment styles are like a template that we take forward with us in life.

Measuring attachment styles

So the development of early relationships – often called ‘attachment styles’ – is extremely important.

Naturally child psychologists realised it would be extremely useful to know how well attached children are to their parents.

But here’s the problem: how do you measure attachment styles?

Infants of eight months old tend not to say very much of any use and parents can’t be trusted.

Clearly psychologists needed to observe the caregiver and baby interacting.

It was well-known child psychologist Mary Ainsworth and colleagues who came up with what has now become standard procedure for investigating the emotional attachment styles between children and caregivers (Ainsworth et al., 1978).

Some have argued that this is the most powerful experiment for studying a child’s social and emotional development.

Ainsworth’s strange situation

Ainsworth based her test of attachment styles on fear, one of the most basic human emotions.

As the baby becomes attached to its caregivers, after about six months, it starts to display fear in two easily repeatable situations:

  • Stranger anxiety: some time after six months of age children usually start to become scared of strangers. This is particularly pronounced when their caregiver is absent.
  • Separation protest: from around the same time, at about six months, children also start to get upset when their caregiver leaves them.

To investigate how infants and their caregivers interact Ainsworth devised a series of interactions which were designed to test how the baby reacted to both stranger anxiety and separation anxiety.

The procedure is like a carefully choreographed ballet, each act lasting about 3 minutes:

  1. Caregiver and infant are placed in the experimental room by the experimenter, who then leaves.
  2. Caregiver does nothing while the infant explores.
  3. A stranger enters, saying nothing for 1 minute, then starts talking to the caregiver. Then, after a further minute, the stranger approaches the infant.
  4. Caregiver then leaves as discreetly as possible so that the stranger and the infant are left alone together.
  5. Caregiver then returns to comfort the infant, then leaves again.
  6. Infant is left all alone.
  7. Stranger enters and begins to interact with the infant.
  8. Caregiver returns and the stranger leaves.

As you can see the strange situation is designed to get more strange for the infant as it goes on.

For a start the infant is in an unfamiliar room, then a stranger enters, then the stranger starts trying to talk to them, then their caregiver is nowhere to be seen.

Each time the stress on the infant is ramped up.

The attachment styles

Analysing the results after repeating the experiment with many infants, Ainsworth discovered a fascinating pattern in the data.

It turned out that the most interesting aspect of the interactions observed was how the baby reacted when the caregiver returned.

This analysis of the infant’s reaction to the mother’s return led to a distinction between three separate types of attachment, one of the ‘good kind’ and two so-called ‘disordered attachment styles’.

1. Secure attachment style

Infants considered securely attached will be reasonable upset when their caregiver leaves but will be happy to see them return and will be quickly soothed.

Extensive research has found that around 70 percent of infants fall into this category.

2. Avoidant attachment (insecure attachment)

Infants with this attachment style show little interest in their caregivers, although they will cry when they leave the room.

Strangely, though, they don’t seem that pleased when their caregivers return, often turning their backs on them and trying to get away.

Around 20 percent of infants fall into this category.

3. Ambivalent attachment (insecure attachment)

Infants with this attachment style initially don’t want to leave their caregiver to explore the room.

Then, like the insecure/avoidant, they cry when their caregiver leaves but then when they return seem to want to be consoled, but resist it.

They seem angry.

About 10 percent of infants fall into this category.

4. Disorganised attachment (insecure attachment)

Later research also identified a further insecure attachment style of disorganised attachment.

These infants don’t show much of a pattern: they seem constantly afraid of and confused by their caregiver.

The stress is often too much for the infant.

This type of attachment style has been associated with depressed caregivers or instances of child abuse.

Causes of attachment styles

An enormous amount of research on attachment styles has gone into examining what factors cause infants to be attached in these different ways.

Much emphasis has been placed on the way the caregiver treats the infant.

Secure attachment styles have been associated with caregivers being (Papalia & Olds, 1997):

  • Sensitive and responsive.
  • Encouraging of mutual interaction.
  • Warm and accepting.

Clearly the reverse of these tends to result in insecure attachment styles.

Some research has also found that the infant’s temperament (personality) is also an important factor in attachment styles.

Consequences of attachment styles

Many researchers have argued that attachment styles have important social, emotional and cognitive consequences.

Some have argued that the more positive an infant’s early attachments are, the more likely it is to successfully separate from the caregiver later in life.

Other benefits of secure attachment styles include (Papalia & Olds, 1997):

  • More self-confidence.
  • More friends.
  • Better adult relationships.

Meanwhile insecurely attached children tend to:

  • Display more negative emotions.
  • Have behaviour problems.
  • Be hostile towards other children.

Attachment styles are a window to the future

Critics of the ‘strange situation’ have argued that it is just too strange.

For example:

  • Why would caregivers specifically resist interacting with their infant?
  • Can infants really keep track of all these comings and goings during the study?
  • Is it valid in different cultures?

Despite these criticisms the ‘strange situation’ has fared relatively well in answer to many of these questions.

It provides a standardised way of examining the very earliest relationships we form with our caregivers.

It is a way of revealing the answers infants have arrived at to four major questions their social and emotional selves are asking:

  1. How do I have good relationships with other people?
  2. What happens when I explore my environment?
  3. What can I achieve?
  4. What do others do when I show that I’m unhappy?

It’s infant’s attachment styles that give us a clue to what answers they’ve formulated to these questions and so a window on both their past and their future.

→ This article is part of a series on 10 crucial developmental psychology studies:

  1. When infant memory develops
  2. How self-concept emerges in infants
  3. How children learn new concepts
  4. The importance of attachment styles
  5. When infants learn to imitate others
  6. Theory of mind reveals the social world
  7. Understanding object permanence
  8. How infants learn their first word
  9. The six types of play
  10. Piaget’s stages of development theory


Theory Of Mind: Test, Example & Experiments

The emergence of theory of mind in children is a vital developmental milestone; some think a failure to develop it is central to autism.

The emergence of theory of mind in children is a vital developmental milestone; some think a failure to develop it is central to autism.

One superpower all psychologists would kill for is the ability to read minds.

Not only would it make psychology research a lot easier, we would be able to experience what it is like to be someone else – a fascinating prospect.

Although telepathy is still science fiction most of us can do something clever that, while only a pale imitation, does allow us to step inside other people’s minds in a limited way.

We can do this because our brains are fantastic simulators – we can, for example, predict the paths objects will take through space and the decisions we should make now to cause a future event.

Similarly, we can put ourselves in other people’s shoes to try and imagine their thoughts, intentions and possible actions.

In fact, without the ability to simulate what other people are thinking we would be lost in the social world.

Theory of mind experiment

Psychologists call this ability to simulate or work out what others are thinking ‘theory of mind’.

The emergence of theory of mind in children is a vital developmental milestone; some psychologists think that a failure to develop a theory of mind is a central component of autism.

The first experiment to provide evidence about when theory of mind emerges using a test of false beliefs was carried out by Heinz Wimmer and Josef Perner from the University of Salzburg (Wimmer & Perner, 1983).

To test the emergence of ‘theory of mind’ the researchers wanted to find out whether children could pass a false belief test.

To pass the test, children have to understand that it’s possible for other people to hold beliefs that are different to their own.

This is a surprisingly tricky task when your brain is so new it’s still under warrantee.

The Maxi task

Wimmer and Perner tested children between 3 and 9-years-old by telling them a story about a boy called Maxi whose mother had brought home some chocolate to make a cake.

When she gets home Maxi sees her put the chocolate into a blue cupboard.

Then Maxi goes out to play.

Meanwhile, his mother uses the chocolate for the cake but happens to put it back in the green cupboard.

When Maxi comes back in he feels hungry and wants some chocolate.

The children in the experiment are then asked, not where the chocolate is, but which cupboard Maxi will look in.

In the experiment the story is also acted out using dolls and matchboxes to make the story explicit for the children.

Test results

The results showed that 3 to 4-year-olds tended to fail the test by pointing to the actual position of the chocolate rather than where Maxi thought it was.

They seemed unable to understand that although they knew where it was, Maxi didn’t.

Wimmer and Perner argued that this was because they could not construct a separate mental model of the world that represented Maxi’s experience – they weren’t capable of a theory of mind.

From about 4 to 5-years-old the situation changed dramatically.

Suddenly, the children tended to point to the cupboard where Maxi thought the chocolate was, rather than where they knew it was.

However in some variations of the experiment children up to 5-years-old still had problems understanding someone else’s false belief.

Finally, at 6-years-old, the children did consistently understand that another person can hold a false belief about the world.

End of innocence

This experiment suggested that at about 4 to 6-years old a range of remarkable skills start to emerge in young children that are vital for their successful functioning in society.

They begin to understand that others can hold false beliefs, they themselves can lie, and that others can lie to them.

From one perspective it is a sad end to innocence, but from another it is a necessary base for a skill required for social success.

At around 4-years-old children are starting to understand that we don’t live out there in the world, we actually create a model of the world in our heads, a model that can easily be wrong.

Criticisms and alternative explanations

Like many child psychology studies, this experiment has sparked much debate about what its results mean.

Here are some of the alternative explanations addressed by the experimenters:

  • Were the kids concentrating? Yes, they correctly answered questions that showed they were concentrating.
  • Had the younger children forgotten the story? No, they were given a memory test which they passed.
  • Were the younger children just pointing at where the chocolate was without thinking about the question? In another experiment children were specifically told to stop and think – this didn’t help the younger children.

While this experiment has been criticised, and other methods have been developed for examining theory of mind in children, tasks like this one are still in use around the world to this day, helping to uncover how and when we first develop the ability to understand other people’s thoughts.

→ This article is part of a series on 10 crucial developmental psychology studies:

  1. When infant memory develops
  2. The mirror test reveals when self-concept emerges in infants
  3. How children learn new concepts
  4. The importance of attachment styles
  5. When infants learn to imitate others
  6. Theory of mind reveals the social world
  7. Understanding object permanence
  8. How infants learn their first word
  9. The six types of play
  10. Piaget’s stages of development theory


Parenting Psychology: 12 Studies Every Parent Should Know

Parenting advice is an impenetrable maze of dos and don’ts, but these studies provide scientific tips on the best way to raise children and be a parent.

Parenting advice is an impenetrable maze of dos and don’ts, but these studies provide tips from psychology on the best way to raise children and be a parent.

One of the many reasons parenting is an impossible job is that everyone is giving you advice, and much of it is rubbish.

Frankly, it’s amazing we’ve all made it this far.

So, bucking the trend of random anecdote and superstition, here are twelve psychology studies about parenting that every parent should know.

1. Parents are happier than non-parents

First some good news for those worried about the burdens of parenting.

In recent years, some studies have suggested that the pleasures of parenting are outweighed by the pains.

“Ha!” said parents to themselves, secretly, “I knew it!”

Not so fast though: research has found that, on average, parents feel better than non-parents each day and derive more pleasure from parenting than from other activities (Nelson et al.,. 2013).

Fathers, in particular, derive high levels of positive emotions and happiness from parenting.

2. Child-centric parenting is worth it

Underlining the pleasures of parenting, research finds that child-centric attitudes are beneficial.

A psychology study by Ashton-James et al. (2013) found that parents who were the most child-centric were also happier and derived greater meaning in life from parenting.

Performing child-care activities was associated with greater meaning and fewer negative feelings.

“These findings suggest that the more care and attention people give to others, the more happiness and meaning they experience.

From this perspective, the more invested parents are in their children’s well-being — that is, the more ‘child centric’ parents are — the more happiness and meaning they will derive from parenting.” (Ashton-James et al., 2013)

So, what’s good for your kids, is also good for you and your parenting.

3. Good parenting involves supporting emotional expression

Parents who encourage their offspring to express their emotions raise happier children, psychological research finds (McKee et al., 2019).

When parents support emotional expression, young adults experience less depression and anxiety.

They are also more mindful, better able to regulate their attention and more open and accepting towards themselves and the world.

Children need ’emotional socialisation’: the ability to understand and deal with one’s own emotions.

Key parenting skills that achieve this include listening, giving comfort and helping children to solve problems.

4. Helicopter parenting may be depressing

As with many things in life, though, it’s a fine line between caring and smothering; especially when children have grown up.

Schiffrin et al. (2013) asked 297 undergraduate students about their parents’ behaviour and how they felt about it.

The study found links between ‘helicopter parenting’ and higher levels of depression amongst the students, as well as lower levels of autonomy, relatedness and competence.

“Parents should keep in mind how developmentally appropriate their involvement is and learn to adjust their parenting style when their children feel that they are hovering too closely.” (Schiffrin et al., 2013)

Other studies have also suggested that helicopter parenting raises maladjusted children.

5. Avoid strict discipline

Around 90 percent of American parents admit at least one instance of using strict verbal discipline with their children, such as calling names or swearing at them.

Rather than helping keep adolescents in line, though, be aware that this may just exacerbate the problem.

A child psychology study of 967 US families and their parenting found that harsh verbal discipline at 13-years-old predicted worse behaviour in the next year (Wang et al., 2013).

And it didn’t help if parents had a strong bond with their children.

The study’s lead author Ming-Te Wang explained:

“The notion that harsh discipline is without consequence, once there is a strong parent-child bond–that the adolescent will understand that ‘they’re doing this because they love me’–is misguided because parents’ warmth didn’t lessen the effects of harsh verbal discipline.

Indeed, harsh verbal discipline appears to be detrimental in all circumstances.”

Studies also find that harsh parenting practices when children are small is linked to smaller brain structures in adolescence.

6. Regular bedtimes are vital to parenting

Regular bedtimes really matter to children’s developing brains, psychology research on parenting finds.

Researchers followed 11,000 children from when they were 3-years old to the age of 7 to measure the effects of bedtimes on cognitive function (Kelly et al., 2013).

The researchers found that:

“…irregular bedtimes at 3 years of age were associated with lower scores in reading, maths, and spatial awareness in both boys and girls, suggesting that around the age of 3 could be a sensitive period for cognitive development.”

Regular bedtimes are important for both boys and girls and the earlier these can be implemented, the better for cognitive performance.

7. Do the chores together

Bringing up happy children is easier if Mum and Dad’s relationship isn’t too rocky.

One frequent bone of contention between parents is the chores.

A trick for achieving marital satisfaction over the chores is to do them together.

When partners perform their chores at the same time–no matter who is doing what — both people are more satisfied with the division of labour (Galovan et al., 2013).

Getting the children involved in chores is also a positive parenting step.

8. Good parenting means letting children see negative emotions

Surprisingly, it is good parenting to allow children to see negative emotions like anger and frustration, psychology research finds (Karnilowicz et al., 2018).

Many parents, though, try to hide all conflicts from their children.

However, children often know when their parents are trying to hide conflict and it confuses them.

They know something is wrong, but see no change in their parent’s behaviour, which is confusing.

Better, say psychologists, to allow children to see healthy conflict and how it is resolved — that is good parenting.

9. Limit infant TV viewing

The American Academy of Pediatrics recommends that children should watch no more than two hours of TV per day after two years of age, and none before that age.

Here’s why: a study that followed almost 2,000 Canadian children from birth found that an extra hour’s TV viewing at 2.5-years-old predicted worse performance later when they attended kindergarten (Pagani et al., 2013).

The more children exceeded this recommendation at 2.5 years old, the worse their vocabulary, math and motor skills were at 5-years-old.

10. Exercise boosts kids’ school performance

Kids are increasingly sedentary and, as I frequently write here on PsyBlog, exercise is a wonderful way to boost brain power, and it has many other benefits.

A study of 11-year-olds has found that moderate to vigorous exercise was associated with increased academic performance in English, Maths and Science (Booth et al., 2013).

These gains from exercise were also seen in exams taken at 16-years-old.

Interestingly, girls’ science results benefited the most from extra exercise.

11. Intense mothering makes stressful parenting

Some women say that parenting is more stressful than being at work.

There are strong links between parenting and stress and guilt.

How can we square this with the reports and research findings that children fill your life with joy and meaning?

It may be down to differences in attitudes to parenting.

In particular, being an ‘intense mother’ may be bad for you.

In their child psychology study of 181 mothers of children under 5, Rizzo et al. (2012) found that mothers who most strongly endorsed the idea that children were sacred and that women are better parents than men, were more likely to be depressed and experience less satisfaction with life.

Yes, nurture your children, but don’t sacrifice your own mental health.

12. Why siblings are so different

Anyone with more than one child will have noticed a curious thing: their personalities are often very dissimilar.

In fact, according to a study by Plomin and Daniels (1987), siblings have no more in common in their personalities than two completely unrelated strangers.

This is very weird given that 50 percent of their genetic code is identical.

The answer isn’t in the genes at all, but in the environment in which children grow up.

Far from having the same environments, each child has:

  • a different relationship with their parents,
  • a different relationship with their other siblings,
  • different friends and experiences at school…

…and so on.

And all these differences add up to quite remarkable dissimilarities between siblings — often such that if they didn’t look alike, you’d never know they were related.

All this means, of course, that because their personalities are often so different, parenting strategies that work with one child, may not work with another.

It’s just one more challenge of parenting!


The Mirror Test For Babies Reveals When The Self Emerges

To this day the ‘mirror test’ or ‘rouge test’ remains the best experiment yet developed for examining the emergence of self-concept in infants.

To this day the ‘mirror test’ or ‘rouge test’ remains the best experiment yet developed for examining the emergence of self-concept in infants.

Most people look out for number one, themselves, which makes it strange to think that there was ever a time when we had no concept of ‘me’.

A simple study dating from the early 70s suggests that before the age of around two years old we can’t recognise ourselves in the mirror.

Because of this study, and the many variations that have followed, some claim that it isn’t until our second birthday that our self-concept emerges.

Rouge test

In 1972 Beulah Amsterdam from the University of North Carolina published a study that has kicked-off decades of research on self-recognition (Amsterdam, 1972).

The study’s procedure was simple.

Infants between the ages of 6 and 24 months were placed in front of a mirror after a spot of rouge had been surreptitiously put on their noses.

Then their mothers pointed to the reflection in the mirror and asked the child: “Who’s that?”.

Researchers than watched infants’ behaviour.

After testing 88 infants Amsterdam could only obtain reliable data on 16 of them – infants will be infants and many didn’t want to play.

From these 16 infants Amsterdam found three categories of response:

  1. 6-12 months: it’s another baby! The child behaves as though the infant in the mirror is someone else – someone they’d like to be friendly with. They display approach behaviours such as smiling and making noises.
  2. 13-24 months: withdrawal. The infants no longer seem particularly happy at catching their own image in the mirror. Some look a little wary while others will smile occasionally and make some noises. One interpretation of this behaviour is that the infants are acting self-consciously here (perhaps demonstrating self-concept), but it could also be a reaction to another child.
  3. 20-24 months onwards: it’s me! From around this age infants start to clearly recognise themselves by pointing to the spot of rouge on their own noses. This strongly suggest they have realised the image is themselves and the spot of rouge is on their own nose.

Although Amsterdam’s results were from a small sample size, they have subsequently been repeated with many more participants.

Also, later studies with control conditions have found infants in this age-range don’t touch their nose if it isn’t marked with rouge.

This showed that touching the nose isn’t somehow a natural reaction for infants to seeing own reflection.

Self-concept or just self-recognition?

Of course this study simplifies a mass of psychological complexity.

Psychologists have raised all sorts of questions about what the mirror test or rouge test reveals.

It could be, for example, that infants just don’t understand faces particularly well until they are around two years old.

Perhaps, then, they develop a self-concept at a much earlier stage.

Alternatively it could be that at around two years old infants develop a solid physical or visual self-concept, but still have little mental self-concept.

In this case all the test is showing is that we know what we look like; perhaps we don’t develop our self-concept until much later in life.

These are just two common explanations, I’m sure you can think of more alternatives.

This multitude of possibilities illustrates one of the major hurdles in child psychology: results are especially ambiguous because only limited tests can be carried out on children.

Still, despite these alternatives, the mirror test has proved remarkably hardy over the years and is still used today while other tests have fallen by the wayside.

The social child

One of the reasons for its resilience is that it seems likely that self-concept might well emerge at this age from all the other things we know about children.

It is from around 2 to 4 years of age that children start to display a rapid increase in their social behaviour.

Being able to distinguish yourself from other people is fundamental to successful social relationships rather than simple interactions.

It seems unlikely that infants would be able to build relationships with others without some limited concept of themselves.

The mirror test has also been used on other animals to test their self-concept, indeed the test was originally carried out on chimpanzees by Professor Gordon Gallup a few years before Amsterdam.

All the great apes ‘pass’ the test, along with dolphins, whales and elephants. In one recent study an 8ft mirror was placed in the elephant enclosure at New York’s Bronx Zoo and the elephants had marks painted on their heads.

Researchers who kept watch on the elephants’ reactions saw them touch the paint marks on their own heads.

It’s no coincidence that elephants, like the other animals that pass the test, have complex social systems.

Basic self-recognition is key to being able to relate to others; with this knowledge infants take their first faltering steps into the social world.

→ This article is part of a series on 10 crucial developmental psychology studies:

  1. When infant memory develops
  2. How self-concept emerges in infants
  3. How children learn new concepts
  4. The importance of attachment styles
  5. When infants learn to imitate others
  6. Theory of mind reveals the social world
  7. Understanding object permanence
  8. How infants learn their first word
  9. The six types of play
  10. Piaget’s stages of development theory


Robert Fantz: The Looking Chamber Experiment

Psychologist Robert Fantz investigated what babies really understand about the world with his looking chamber experiment.

Psychologist Robert Fantz investigated what babies really understand about the world with his looking chamber experiment.

Robert Fantz, a developmental psychologist, in his 1961 series of experiments, investigated what babies really understand about the world.

The eyes of tiny infants look glazed and they mostly seem concerned with the bare necessities of life.

What do they understand about the world and how can you possibly find out, given that babies are not so hot on answering complex questions about their perceptual abilities?

In 1961, when Fantz carried out his experiment, there wasn’t much you could do to find out what was going on in a baby’s head – other than watch.

And watching the baby is what he did.

An enduring feature of human nature is if there’s something of interest near us, we generally look at it.

So Fantz set up a display board above the baby to which were attached two pictures (Fantz, 1961).

On one was a bulls-eye and on the other was the sketch of a human face.

Then, from behind the board, invisible to the baby, he peeked through a hole to watch what the baby looked at.

The results

What he found was that a two-month old baby looked twice as much at the human face as it did at the bulls-eye.

This suggested that human babies have some powers of pattern and form selection.

Before this it was thought that babies looked out onto a chaotic world of which they could make little sense.

In modern psychology the descendants of this experiment are still used today to find out what babies understand about the world.

These have discovered that we’re remarkably early developers.

At one month we can follow a slow-moving object.

At two months we can move both our eyes together and begin to appreciate how far away things are.

At three months we can tell the difference between members of our family (Hunt, 1993).

As a result of these and similar studies, psychologists have suggested that we are born with a definite preference for viewing human faces.

This would certainly make evolutionary sense as other human faces hold all sorts of useful information which is vital for our survival.

Not a bad set of conclusions from simply watching a baby’s eyes!


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