Pages 250-300:
"Behavioral genetic studies have proved beyond a shadow of a doubt that heredity is responsible for a sizable portion of the variations in people’s personalities.
A child can have characteristics seen in neither of her parents. But there is a statistical connection—a greater-than-chance likelihood that a person with psychological problems has a biological parent or a biological child with similar problems. Heredity is one of the reasons that parents with problems often have children with problems. It is a simple, obvious, undeniable fact; and yet it is the most ignored fact in all of psychology. Judging from the lack of attention paid to heredity by developmental and clinical psychologists, you would think we were still in the days when John Watson was promising to turn a dozen babies into doctors, lawyers, beggarmen, and thieves.
The evidence shows that the environment has an effect on criminality but it doesn’t show that the relevant environment is the home; in fact, it suggests a different explanation. When both twins or both siblings get into trouble, it is due to their influence on each other and to the influence of the peer group they belong to.
Are some people born bad? A better way of putting it is that some people are born with characteristics that make them poor fits for most of the honest jobs available in most societies, and so far we haven’t learned how to deal with them. We are at risk of becoming their victims but they are victims, too—victims of the evolutionary history of our species. No process is perfect, not even evolution. Evolution gave us big heads, but sometimes a baby has a head so big it can’t fit through the birth canal. In earlier times these babies invariably died, as did their mothers. In the same way, evolution selected for other characteristics that sometimes overshoot their mark and become liabilities rather than assets. Almost all the characteristics of the “born criminal” would be, in slightly watered-down form, useful to a male in a hunter-gatherer society and useful to his group. His lack of fear, desire for excitement, and impulsiveness make him a formidable weapon against rival groups. His aggressiveness, strength, and lack of compassion enable him to dominate his groupmates and give him first shot at hunter-gatherer perks. Unlike the successful hunter-gatherer, however, the career criminal tends to be below average in intelligence.
Having a father or not having one: How much difference does it make for an ordinary child in a developed society? I will not deny that children are generally happier if they have two parents; I will not deny that they are happier if they have evidence that both parents care about them and think well of them. sequelae. This book is about the long-term consequences of what happens while you’re growing up. Do children with fathers turn out better in the long run than children without fathers? And if they do turn out better, is it because they had a father? Most people think so.
But the graphs and tables in McLanahan and Sandefur’s book contain some curious findings: a lot of things you’d think would matter turn out not to matter. The presence of a stepfather in the home doesn’t improve the kids’ chances at all. Nor does contact with the biological father outside the home: “Studies based on large nationally representative surveys indicate that frequent father contact has no detectable benefits for children.” Nor does having another biological relative living in the home: the presence of a grandmother doesn’t help. In homes with live-in grandmothers, kids are left alone less often than in homes with two biological parents, yet that doesn’t stop them from dropping out of school or getting pregnant. In homes with stepfathers, kids are given as much supervision as in homes with biological fathers—they are as likely to have their whereabouts monitored or their homework checked—yet that doesn’t stop them from dropping out of school or getting pregnant. The number of years the kids spend in a single-parent family also doesn’t matter: those whose fathers stuck around until they were on the brink of adolescence are no better off than the ones whose fathers went bye-bye when they were babies or, for that matter, fetuses.
Let me show you how it might be possible to account for the unfavorable outcomes without reference to the children’s experiences in the home or to the quality of parenting they receive there.
Most single mothers are nothing like Murphy Brown: most of them are poor. Half of all homes headed by women are below the poverty level. Divorce usually leads to a drastic decline in a family’s standard of living—that is, in the standard of living of the ex-wife and the children in her custody.
But by far the most important thing that money can do for kids is to determine the neighborhood they grow up in and the school they attend. Most single mothers cannot afford to rear their children in the kind of neighborhood where my husband and I reared ours—the kind where almost all the kids graduate from high school and hardly any have babies. Poverty forces many single mothers to rear their children in neighborhoods where there are many other single mothers and where there are high rates of unemployment, school dropout, teen pregnancy, and crime.
Neighborhoods have different cultures and the cultures tend to be self-perpetuating; they are passed down from the parents’ peer group to the children’s peer group.
The analysis churned out by the researchers’ computer was boringly similar to those of other behavioral genetic studies: about half of the variation in the risk of divorce could be attributed to genetic influences—to genes shared with twins or parents. The other half was due to environmental causes. But none of the variation could be blamed on the home the twins grew up in. Any similarities in their marital histories could be fully accounted for by the genes they share. Their shared experiences—experienced at the same age, since they were twins—of parental harmony or conflict, of parental togetherness or apartness, had no detectable effect.
When life at home is disrupted, the child’s behavior at home is of course disrupted, and so are the emotions associated with the home. These are the changes the researchers are seeing. If they want to find out how the child’s life outside the home is affected by the parents’ divorce, the researchers will have to collect their data outside the home, and if they want to do it right they will have to use unbiased observers—observers who are unaware of the child’s family situation. What the researchers will find under these conditions, judging from the behavioral genetic data I mentioned earlier, is that parental divorce has no lasting effects on the way children behave when they’re not at home, and no lasting effects on their personalities."