Thursday, September 26, 2019

Early experience, not genes, shapes child abusers (?)

So it is claimed below. It may be true that most child abusers were themselves abused in childhhod but it does not follow that abuse always makes one an abuser.  Rather to the contrary from some examples I have seen: People are often determined that their kids will have a better deal than they had. So precluding a genetic influence on child abusers is dumb and does, I believe, miss the big story:  Child abusers tend to be low IQ people, low IQ males in particular. So it would seem that child abusers will always be with us.  Eugenics no longer has a constituency.

Stories of children killed or disabled by those responsible for them always grieve me greatly but the one consolation I have is that the murdered kid would probably have turned out pretty dumb too -- though that is not at all certain.

I don't know if this study below by Darius Maestipieri, a primate expert at the University of Chicago, is really worth commenting on. It purports to show that child abusers get that way not by genetic inheritance (e.g. by being born stupid, uncontrolled or aggressive) but by being abused themselves as children. The research concerned, however, was based on a small group of Macaque monkeys and I cannot see how the results can be statistically significant, let alone meaningful in any other way.

And this finding would seem to contradict their conclusion anyway: "almost half of those raised by abusive mothers did not become abusers themselves." That seems to indicate genes at work to me. And I won't ask questions about measures taken to preclude observer bias. No good beating a dead horse

Child abuse may be more of a learnt behaviour than a genetic trait, new research on monkeys suggests. If true, the understanding may provide the opportunity to break the cycle of abuse that runs in some families.

As many as 70% of parents who abuse their children were themselves abused while growing up. Maternal abuse of offspring in macaque monkeys shares some similarities with child maltreatment in humans, including its transmission across generations. This pattern of abuse has led to speculation that it may have a genetic basis.

Darius Maestipieri, a primate expert at the University of Chicago, US, tested the theory by observing a population of macaques across two generations. He took some of the newborn female infants from the group and cross-fostered them among the mothers, about half of which were abusers.

In the next generation, he found that 9 of the 16 females who were abused in infancy by their biological or foster mothers turned out to be abusive towards their own offspring.

But none of the 15 females raised by their non-abusive biological or foster mothers maltreated their offspring, including those whose biological mothers were abusers. This indicates that intergenerational transmission of abuse is not genetically caused.

Protective personality

“This study into primate patterns of abuse can be directly related to human abuse,” argues Maestipieri. “What it shows is that the effect of experiencing abuse first-hand or through experiencing siblings being abused is very significant in determining whether somebody will become an abuser.

“But it’s also interesting to note that almost half of those raised by abusive mothers did not become abusers themselves,” he told New Scientist. “We should try to discover what it is about these infants’ personalities or socially supportive environment that protected them from abusive effects.”

Chris Cloke, head of child protection awareness at the UK’s National Society for the Prevention of Cruelty to Children, is wary of applying animal studies directly to humans. But he adds: “We know the damaging consequences of child abuse can last into adulthood and affect the way children are brought up. Experiences of abuse in infancy can be particularly important as the brain develops fast in the first year of life.

He also notes: “With the right sort of help people with abusive childhoods can often grow up to be loving parents.”

Maestipieri believes that while some abuse is learnt through direct or indirect experience, physiological changes incurred during abuse may predispose behaviour patterns. “There is evidence that early trauma causes people to become more susceptible to stress, and less able to cope with emotionally challenging situations, so that they could react more easily by ‘losing it’,” he says.

Macaques who abuse their offspring do so early on, during the first three months of life. Abuse, which occurs about once an hour, is brief and takes the form of being overly controlling and violent towards the infant. Actions include biting infants or treating them like an inanimate object – dragging the baby around by its leg or tail, tossing it in the air, or stepping on it.

Journal reference: Proceedings of the National Academies of Science (DOI: 10.1073/pnas.0504122102)