Why your personality runs hot and cold

We constantly transform who we are by what we do, veteran psychologist Walter Mischel tells JP O’Malley

Why your personality runs hot and cold

THE last time you were introduced to a stranger, did you form an impression about them immediately? American psychologist, Walter Mischel, 84, says this is normal.

“What you know about me, so far, is based on whatever knowledge you’ve acquired after talking to me. But it’s going to miss 90% of what I am really like,” he says.

“The reason for this goes way back to our evolutionary history. Forming broad impressions is good for dangerous situations. But, very often, they are wrong,” Mischel says.

In his groundbreaking 1968 book, Personality and Assessment, Mischel said personality study was misunderstood.

Previously, the assumption was that an individual’s behaviour should be consistent across all situations.

But Mischel said that human behaviour was a result of both the situation and the environment. In personality psychology, the tradition is to study a person’s behaviour in conjunction with the so-called ‘big five’.

These can summarised as OCEAN, meaning: openness to experience; conscientiousness; extraversion; agreeableness, and neuroticism.

By placing our faith in these general terms, Mischel says that we risk confusing constructions of behaviour with the cause of behaviour.

In ‘A Hot/ Cool System Analysis of Delay of Gratification’, a paper Mischel published with Janet Metcalfe, in 1999, in the Psychological Review, he analysed how a person’s thoughts interacted to enable or prevent self-control. The paper spoke in detail about the emotional hot system and the cognitive cool system.

“The hot system is full of things that we [humans] share with other animals. And they have to do with basic drives and needs.

“The cool system is where reason, empathy, imagination and problem-solving come from. When stress is high, the hot system becomes dominant, and when stress is low, the cool system becomes dominant,” says Mischel.

“The two systems are in a reciprocal relationship with each other. While the hot system may be useful, it can also make you extremely irrational. Essentially, it makes it very difficult to delay gratification.”

Which brings us to the other side of the psychologist’s work: resistance to temptation and self-control.

This was exemplified in Mischel’s famous ‘marshmallow experiment’, conducted over four decades ago at Stanford University.

The basis of the experiment was simple: small children, aged between three and five years old, were left alone in a room with a single marshmallow.

Mischel told the children they could eat the marshmallow immediately, or wait until he came back with another. If the child wanted another marshmallow, they rang the bell to indicate their choice.

The aim of the experiment was to monitor delay of gratification in children.

Mischel predicted the following: those children who were able to wait for the second marshmallow would, in later years, have stronger resistance to other temptations and be able to manage their impulse control more adequately.

The results of the original tests were stored on file.

Later, Mischel would use them to correlate with a number of follow-on experiments. The first one, in 1988, showed that children who delayed gratification for longer periods were described by their parents in their teenage years as significantly more competent.

The follow-up study, in 1990, showed that those who had more success in delaying gratification had higher SAT scores, a lower body mass index, a better sense of self-worth, pursued their goals more effectively, and coped more efficiently with frustration and stress.

In 2011, with the aid of technology, Mischel did the most comprehensive follow-up study to date.

The results feature heavily in his new book, The Marshmallow Test: Mastering Self-Control.

The experiment tested whether individuals who were less able to delay gratification as children would, as adults now in their mid-40s, show less impulse control.

Mischel explains the results.

“The study showed more activation in the appetitive areas of the brain, which is connected to obesity and to drug addiction, was actually stronger for the kids who had rung the bell earlier.”

In his new book Mischel says the conclusion is inescapable: who we are emerges from the tightly intertwined dance between our environment and our genes, and causation can’t be reduced to either part alone.

In other words: the age-old debate about nature versus nurture (in terms of shaping human behaviour) cannot be boiled down to either genetics or our environment. Both are equally important, he says.

“We are constantly able to transform what we become, by what we do, what we eat, how we live, and in how our relationships play out,” says Mischel.

More in this section

Puzzles logo

Puzzles hub

Visit our brain gym where you will find simple and cryptic crosswords, sudoku puzzles and much more. Updated at midnight every day.

great irish summer

From walking and hiking, to day trips and camping, your guide to holidays at home in 2021


The best food, health, entertainment and lifestyle content from the Irish Examiner, direct to your inbox.

Sign up