So far in this series on the top ten psychology studies, the research has lumped us all together in one group and asked what psychological research says about all of us. The studies have asked questions about how people’s emotions, memories and perceptions work.
What they haven’t asked is what can psychologists tell us about the systematic differences between people? To answer this question I have to break the pattern just this once and include two studies, from two apparently warring factions of personality psychology.
Eysenck and the personality
The first is one of the earliest studies in a long line of research by Hans Eysenck. Eysenck was influenced by Greek philosophy in his search for human personality. The Greeks thought there were four categories of person: the melancholic , the sanguine, the choleric and the phlegmatic. Eysenck, instead of thinking people could be pigeon-holed this neatly suggested people could be described on a sliding scale of each of these factors. He had a hunch that personality differences between people could be described on two ‘dimensions’. “Extraversion is the degree to which a person is outgoing and neuroticism is the degree to which they are emotionally stable (or not).”These dimensions were introversion versus extraversion and neuroticism versus stability. Extraversion is the degree to which a person is outgoing and neuroticism is the degree to which they are emotionally stable (or not).
If you imagine these two dimensions at right angles to each other then you have a big cross with four quadrants on which everyone’s personality falls somewhere. For example, if you are highly introverted and highly neurotic, you are an extremely anxious person. On the other hand if you are highly neurotic but extraverted then you would be an hysteric (Hampson, 1988).
Eysenck (1944) tested this theory by using information from 700 patients at a military hospital. He asked their treating psychiatrists to rate patients on a number of scales which included ‘degraded work history’, ‘sex anomalies’ and ‘dependent’ along with a host of others. From these he used a technique called factor analysis from which these two dimensions of introversion/extraversion and neuroticism/stability emerged.
“Eysenck made an exciting, bold statement…”When you think about it, Eysenck made an exciting, bold statement: every human’s personality can be classified on just two sliding scales. Since then personality theory has moved on and now theorists have settled on five sliding scales. This scale is going strong and appears to describe some of the systematic ways in which people differ. Well it would do, if there wasn’t one rather large fly in the personality psychologist’s ointment: the situation.
Mischel and the situation
In 1968, Walter Mischel dropped a bomb on personality theory with his innocuously titled study, ‘Personality and Assessment’. Mischel thought the evidence showed tests such as Eysenck’s were almost worthless because they didn’t take into account the situation. “what is a personality test really telling us about a person?”It is clear, he argued, that people behave quite differently depending on the situation. Imagine you’re late for an appointment, you’re sitting in huge traffic jam, do you behave the same way as when you’re sitting at home, relaxed? It not, then what is a personality test really telling us about a person?
Mischel (1968) reviewed a series of studies that attempted to predict people’s behaviour from their personality scores. He found there was little consistency in people’s behaviour across situations. In fact, he concluded there was as little as 9% of agreement between the way people behaved in different situations. Or, put the other way around 91% of the differences in people’s behaviour in different situations couldn’t be accounted for by personality tests.
Situation versus personality
The work of both Eysenck and Mischel was crucial in forming what became a massive debate in psychology. Mischel’s particularly, as it made many psychologists ask what was the point of studying personality if it predicted so little. “Eysenck was saying you are what’s inside, your personality, and Mischel was saying you are what is outside, the situation.”These two studies don’t just encapsulate the debate about personality and the situation but also highlight another constant battle in psychology, between the power of internal and external forces, your own thoughts and feelings versus those of society. Eysenck was saying you are what’s inside, your personality, and Mischel was saying you are what is outside, the situation.
It doesn’t take a genius to point out they were both right in their own ways. People do seem to be different in certain aspects, for example some people are more sociable than others. But people also show remarkable similarities in certain situations, e.g. their need to conform. The trick is in finding the balance between the two, a problem at which psychology is still working hard. Nevertheless, both Mischel and Eysenck’s work gave an important insight into what it means to be human, what it means to be an individual.
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
Image credit: Haags Uitburo
Top Ten Psychology Studies
→ This post is part of a series on the top ten psychology studies.
- What Are Babies Watching?
- The Magical Number Seven, Plus or Minus Two
- Revolutionary Treatment of Depression
- Even 24,576 Measurements Couldn’t Prove Plants Have Souls
- Memory Manipulated After The Event
- Personality or Situation? The Psychology of Individual Differences
- Nobel Prize-Winning Research on Risky Decision Making
- Sigmund Freud and Unconscious Mental Processes