At a meeting last year, Sarah Johns at the University of Kent in Canterbury, UK, reported that in her study of young women from a range of socioeconomic backgrounds in Gloucestershire, UK, those who perceived their environment as risky or dangerous, and those that thought they might die at a relatively young age, were more likely to become mothers while they were in their teens. "If your dad died of a heart attack at 45, your 40-year-old mum has got chronic diabetes and you've had one boyfriend who has been stabbed, you know you've got to get on with it," she says.
Fathers in deprived neighbourhoods are more likely to be absent, which could be because they are following "fast" strategies of their own. These include risky activities designed to increase their wealth, prestige and dominance, allowing them to compete more successfully with other men for sexual opportunities. These needn't necessarily be antisocial, but often they are. "I'm thinking about crime here, I'm thinking about gambling," says Nettle, and other risky or violent behaviours that we know are typical of men in rough environments. A fast strategy also means a father is less likely to stick with one woman for the long term, reducing his involvement with his children.
Once you are in a situation where the expected healthy lifetime is short whatever you do, then there is less incentive to look after yourself. Investing a lot in your health in a bad environment is like spending a fortune on maintaining a car in a place where most cars get stolen anyway, says Nettle. It makes more sense to live in the moment and put your energies into reproduction now.These fast strategies, unfortunately, form a feedback loop: children brought up with minimal investment by fast-strategy parents are more likely to perceive their prospects as bleak and engage in similar strategies (studies have shown daughters of absentee fathers being more likely to become pregnant in their teens, for example). Meanwhile, junk-food diets stunt cognitive development, further sabotaging attempts to break the cycle.
The upshot of all this is that, if Nettle's theory holds, campaigns against unhealthy or antisocial behaviours are merely treating the symptoms, and real improvements can only come from addressing the underlying causes of such insecurity, i.e., poverty and uncertainty. Of course, actually doing so is a lot more expensive and could prove electorally unpopular, especially when opportunistic politicians are willing to promise cheaper solutions and voters are eager to believe that they will work.
That's a good point; it's hard to remember that the "underclass" was, until recently, the norm.
This is great science - interesting and thought-provoking stuff that helps us understand things that matter. If this kind of stuff were taught in schools, science would become a popular subject.
One thing that struck me is how odd it is that we find this odd. For most of human history, uncertainty, poverty and a short life span have been normal. So human sexual psychology evolved in an environment in which the "breed young and often" approach described in the article was the only reasonable strategy.
Quite recently (it's just a few decades), and in only a few countries, this no longer holds, and some people can confidently expect a long, well-fed life. Suddenly, "get an education and a career before breeding" makes sense.
But brains don't evolve as quickly as environments. I wonder if this is the reason adolescents continue to have strong sexual urges before it is economically sensible to breed?