[lit-ideas] Early experience, not genes, shapes child abusers

22:00 27 June 2005 
NewScientist.com news service 
Gaia Vince 

http://www.newscientist.com/article.ns?id=dn7587


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 (vol 102, p 
9276)

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