IT BEGAN with some marshmallows. . . . Those who had resisted, he found, did better at school than those who had given in. As adults they got better jobs, were less likely to use drugs and got into trouble with the law less frequently. Moreover, children’s family circumstances suggested that impulsive behaviour was as much learned as inherited. This suggested that it could be unlearned—improving the child in question’s chances in life
. . . . Recent observations, however, raise the possibility that developing self-control is not always an unalloyed good. Work published two years ago by Gene Brody of the University of Georgia, who looked at a group of young black Americans, showed that those who exhibited self-control as teenagers did indeed get the expected benefits. But if such self-controllers came from deprived backgrounds, they developed higher blood pressure, were more likely to be obese and had higher levels of stress hormones than their less-self-controlled peers. That correlation did not apply to people who started farther up the social ladder.
Dr Brody and his colleagues have followed this study with one that comes to an equally astonishing conclusion: for people born at the bottom of the social heap, self-control speeds up the process of ageing. This research, just published in the Proceedings of the National Academy of Sciences, looked at DNA methylation . . . . Dr Brody and his colleagues followed almost 300 black American teenagers of different backgrounds as they aged from 17 to 22. For the first few years the researchers assessed their volunteers’ levels of self-control, and also looked for signs of depression, aggression and drug use. They assessed, too, those volunteers’ socioeconomic backgrounds. But the last examination, when participants were 22 years old, was different. Then, the researchers took a blood sample, recorded the DNA-methylation patterns of cells in it, and worked out how much these deviated from the pattern expected at that particular age. . . . for people from high-status backgrounds, higher self-control meant lower cellular ages. For those whose background was low-status, the reverse was true. Their cells were ageing faster. Add this to the previous data on blood pressure, stress and obesity, and the medical prognosis of these initially low-status individuals does not look promising. . . .
No biologist would find surprising the idea that an animal—any animal—which was rising through its social hierarchy would find the experience stressful. And research into gene methylation, part of a field called epigenetics, suggests changing methylation patterns are a common response to changing circumstances as well as changing age, as the body’s physiology struggles to keep up.From the Economist.
Another possibility, of course, is that self-controlled is less of a learned behavior, and more of a genetic one, a flaw that could arise because researchers inferred from their never perfectly clear data because they interpreting their results at a time when a prevailing emphasis on nurture v. nature tended to overstate nurture effects was at its apex. Impulsivity is part of a complex of personality traits that are about 50% inherited and some sub-aspects of that personality trait may be even more strongly inherited.
If impulsivity is strongly inherited, then higher blood pressure, obesity, stress hormones and cell aging could reflect the costs of struggling against natural genetic inclination, rather than the stress effects of social climbing.
Either way, the question is: Are the well documented benefits of impulse control are worth the struggle for those at the bottom of the social pyramid?
I think that most people would say that they are. But, it is also worth recognizing that social climbing through behavior modification is personally costly for the people who do it.