The nature-nurture debate is over\u2014at least when it comes to what makes people different from one another. There are three laws of behavioral genetics. They\u2019re simple enough, even though they dispute the long assumed Blank Slate.<\/p>\n 1. All human behavioral traits are heritable. First law<\/strong>. A trait is any stable property of a person that can be measured by psychological tests. Variances can be measured. Heritability can be measured. E.g. between twins, but also among siblings. Results come out roughly the same way. Examples, including the five personality traits, 375m (these are openness to experience; conscientiousness; extroversion-introversion; antagonism-agreeableness; and antagonism). Still, behavioral genetics doesn\u2019t explain what people have in common, i.e. universal human nature. Nor does it identify if genes cause the traits, only that there\u2019s a correlation between them. Radical scientists have tried to discredit this law. Examples. Such attacks are obviously political. And they easily slide from 50% to 100%, from \u2018some\u2019 to \u2018all.\u2019<\/p>\n Second law<\/strong>. So, the environments play as important a role as the genes? Not so fast. Only *shared* environments. Not anything we don\u2019t share with our siblings. There are various techniques to study these effects. We find that effects of shared environments are small, even negligible. \u201cWhatever experiences siblings share by growing up in the same home makes little or no difference in the kind of people they turn out to be.\u201d This does not apply to other kinds of differences\u2026<\/p>\n Third law<\/strong>. A lot of variation is not accounted for by genes or families. Thus even identical twins raised together are far from identical in intellects or personalities. Identical twins are 50% similar whether they grow up together or apart.<\/p>\n It took a while for these ideas to sink in. E.g. Sulloway\u2019s Born to Rebel<\/strong> in 1996. Harris, in The Nurture Assumption<\/strong> in 1998, brought the three laws into the open and challenged conventional wisdom about child-rearing. Rousseau made children noble savages, who could be shaped in many ways. Thus many things were blamed on parents. By now most parents understand the basic advice about raising children, p382. (Provide varied experiences; read and talk to babies; interact and communicate; set limits; no physical punishment; shower them with love and approval.) Some began to question it. The idea of full-time parenting, short-order cooking, never damaging a child\u2019s self-esteem. In fact there are wide differences in parenting styles. But they don\u2019t much affect how children turn out. Examples. Problems with surveys. Children turn out pretty much the same whatever their parents do, 386t.<\/p>\n Decades of studies have shown that, all things being equal, children turn out pretty much the same way whether their mothers work or stay at home, whether they are placed in daycare or not, whether they have siblings or are only children, whether their parents have a conventional or open marriage, whether they grow up in an Ozzie-and-Harriet home or a hippie commune, whether their conceptions or planned, were accidental, or took place in a test tube, and whether they have two parents of the same sex or one of each.<\/p><\/blockquote>\n [[ Naturally conservatives will simply not believe such studies, they *know* what is right, and what they ‘know’ always corresponds to simple tribal morality. ]]<\/p>\n Even growing up without a father may not cause problems directly, but rather indirectly; true causes are more likely poverty, frequent moves, and tendencies to be impulsive and quarrelsome. [[ What affected my own social development were my family’s frequent moves, or more precisely, frequent changes of schools. ]]<\/p>\n In the 1990s parents were responsible for everything, especially in the first three years. The claims were discredited. So, what is it in the environment that does affect children?<\/p>\n One hope was that parents could help their children by interacting with them, on individual levels. Yet differences in children are preexisting. But it wouldn\u2019t work out in practice\u2026 They\u2019d had to treat different children in opposite ways. And it would make parenting advice useless; what would help some children would make others worse. OTOH birth order might have an effect; Sulloway’s book again. [[ Though his notions, about oldest children being the most conservative, don\u2019t describe my family at all. ]] The effects he predicted haven\u2019t appeared.<\/p>\n Outside the home, then? People model themselves after their peers, not their parents. Harris\u2019s explanation. Group Socialization theory. Children don\u2019t strive to become like their parents. Child-obsessed parenting is a recent practice; in foraging societies children, once the next one comes along, and dumped into play groups with other children. Author was attracted to Harris\u2019s theory since it explained problems with language, his field. Examples of children of immigrants, etc. Behaviors like smoking, trouble with the law, are influenced not by parents but by peers.<\/p>\n So how was Harris\u2019s book received? Author presented it in a few pages of How the Mind Works<\/strong>. Reviewers attacked the passage. Margaret Wertheim was confused about \u2018family dynamics\u2019. Other examples. Harris got more venom from the political right. Because it downplays the importance of the traditional family. Hillary wrote It Takes a Village<\/strong>. Other examples of attacks on Harris.<\/p>\n Did Harris solve the mystery of the third law? Not exactly. Do peer groups affect personalities? Perhaps; different children join different peer groups. But again, from twins: peer groups don\u2019t explain what makes them different. Perhaps something like niches within a group. Perhaps matters of chance. Details. We know this happens in other animals. You could even call it fate.<\/p>\n People hope this isn\u2019t true. At the same time, this absolves parents from blame for how their kids turned out. Does it matter how parents treat their children? Of course. Parents have the power to make their children\u2019s lives happy, or not. And parent and child have a relationship; it\u2019s not about molding the children, any more than doing so to a spouse. Be nice to your kids, so they\u2019ll be nice to you when you\u2019re old. Most people understand these things.<\/p>\n","protected":false},"excerpt":{"rendered":" This time: Children. The old nature vs. nurture debate is too simplistic and binary. Given implications of our innate human nature, the (by now unsurprising) takeaway here is that parents have far less influence on their children than people have … Continue reading ![\"\"](\"https:\/\/www.markrkelly.com\/Blog\/wp-content\/uploads\/2024\/05\/pinkerblank_400x555-216x300.jpg\"){kind=spacer}
<\/a>–Ch19, Children<\/strong><\/em><\/p>\n
\n2. The effect of being raised in the same family is smaller than the effect of the genes.
\n3. A substantial portion of the variation in complex human behavioral traits is not accounts for by the effects of genes or families.<\/p>\n