The classic study on self-control is the marshmallow experiment, conducted by Walter Mischel. Children were asked to resist eating a single marshmallow, and if they managed it they would be rewarded with two marshmallows later on. The most successful students would sit on their hands, sing, or otherwise distract themselves. One young overachiever even took a nap! Later in life, the children who could resist the marshmallow best did better on almost every measure of life outcomes. (Interestingly, one measure they didn’t do better on was avoiding problem drinking: alcoholism did not appear to correlate with lack of willpower).

How Children Succeed follows on from this work and examines the importance of character (things like self-control, optimism, and grit), not just intelligence, in adult outcomes. Tough points out that measures of character are as good at predicting success in later life as measures of intelligence, and that measures of intelligence can be disturbingly flawed: one study found that offering M&Ms for each correct answer increased IQ scores by 12 points for kids at the bottom of the distribution.

One of the most fascinating chapters, though, is on stress. On the savannah, when we see a lion every possible system activates in order to get us out of trouble: we breathe faster, we have more white blood cells, our muscles tense, etc. This response is essential for survival, but wears our body out over time. He argues the same happens today when people have stressful childhoods: their systems become overloaded and wear out, and they find it difficult to regulate thoughts and emotions later in life. If we measure stress levels as children and control for them, the effect of poverty on adult outcomes almost disappears.

Perhaps even more interestingly, evidence from rats suggests the opposite of some suggested parenting styles: the rats with nurturing and attentive mothers while they are young become more independent and self-reliant when they are older.

The evidence is clear that character is extremely important to outcomes, and it’s not clear our modern society accounts for that. Policy interventions are therefore critical. Stress reduction among children can contribute to measures meant to tackle poverty, and ensuring that students rate themselves on non-cognitive measures can go a long way to encouraging the right behaviour, as some charter schools that offer a character report card have discovered. Intelligence is not enough, as many an intelligent adult can tell you.

You can keep reading How Children Succeed here (or in the UK or Canada) – for those interested in education, I’d highly recommend it. Or, join the Subtle Illumination email list to your right, and we can try to build our characters together.