Biological roots to domestic violence?

Biological roots to domestic violence?
© 2012 EPFL

In an experiment carried out with rats at EPFL, it was observed that aggressive behavior passed from one generation to the other, even without any contact between the parent and its offspring. Researchers are exploring several approaches to explain the results.

Childhood traumas alone do not explain the development of - at least in the case of rats. As part of a study conducted at EPFL, researchers from the Brain Mind Institute were able to show that purely biological elements played a crucial role in the development of . This study has been published online by the journal Nature inTranslational Psychiatry.

Carmen Sandi and her team’s research targets a deeper understanding of human domestic violence. "But it is unimaginable to isolate human beings from social interaction to see the personality they would develop," indicates the researcher. Hence, she carried out experiments with rats in order to conduct her research.

The experiment begins with male rodents who were exposed several times during their youth – that is, around puberty – to two types of psychological stress. They were thus subjected to short sessions in which they were put in a location without any place to hide, which they by nature dislike. On the other hand, researchers also exposed them to the characteristic odor of one of their natural predators, the fox.

Like father, like son

As adults, when these rats were put in contact with females, they showed a more aggressive behavior towards them than their peers who had not been stressed during adolescence. But the most interesting part was still to come. "The male offspring of these stressed rats showed an aggressive behavior towards females, just like their fathers had done", Carmen Sandi continues "and yet our protocol had allowed us to eliminate any 'social influence' as the rat couples had been separated before the birth of their offspring."

For researchers, this demonstrates that certain behavioral traits are rooted in biological factors and not only in social ones like imitating a role model.

Many possible explanations

As for the females subjected to stressed males, they went through considerable behavioral, hormonal and neurological changes. The other females, put into relationships with only second generation aggressive males - who accordingly had not been directly stressed - showed exactly the same characteristics. This proves that the violence they suffered translated into long-term damage which was not exclusively psychological.

In the wake of this research, several additional studies will try to explain more accurately the mechanisms at work. The reasons for the transmission of aggressiveness in males could be epigenetic (inherited changes in the expression of certain genes), or might be related to physiological changes in the mother during pregnancy, observed after exposure to an aggressive male. An imperceptible deficit of maternal care in the ’s first days of life could also play a role in some cases, but the study in question only took into account families where such care did not differ from the one provided by an unstressed mother.

It would obviously be risky to immediately extrapolate these results to humans. Many analogies could, however, "lead us to revise the way we regard the origin of the development of domestic violence as exclusively psychological and social", Carmen Sandi explains. If biological factors do not explain everything, they constitute nevertheless a heavy legacy, which may favor drifting towards such kinds of behaviors. "From this knowledge, we can work to develop treatments that would be able to block the expression of this biological transmission," the researcher concludes.

Explore further

Stress can affect future offspring

Provided by Ecole Polytechnique Federale de Lausanne
Citation: Biological roots to domestic violence? (2012, May 2) retrieved 24 March 2019 from
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User comments

May 02, 2012

First of all let me state that I am a layman not a scientist but even I was able to spot some glaring omissions from this report.
The reporting given above is highly selective and gives the impression of being deliberately misleading. The reason I say this is that she (Carmen Sandi )apparently only tested what happens to female rats when placed with male rats (and not the other way around)that were stressed or where their fathers were stressed. Also inclusion of a paragraph entitled "Like father, like son" show I think the bias underlying this research. This is shoddy reporting and or disgraceful science and certainly not worthy of this publication.

May 02, 2012
For an evolutionist, domestic violence is just another survival mechanism from some random mutation. It is neither wrong nor right. For a Christian, domestic violence is evil because it goes against the Words of Jesus: love your neighbour. The Christian worldview is moral, plausible and cogent in light of human experience.

Your insinuation contradicts itself. "Evolutionist" and "Christian" are in no way mutually exclusive, and it has been proven that there are human specimens that belong to both groups/labels, yet you claim that they have contradicting perceptions of this THEORETICALLY POSSIBLE phenomenon. Might want to review your logic and premises, notably your definitions of "evolutionist" and "christian".

Stop being such a cultist troll, okyesno. Each and every single one of your posts uses valid logic, but is always based on faulty premises, incorrect/insufficient information, or cherry-picked data without context. Fix it, or give up. I can coach/teach you if needed.

May 02, 2012
We can't deny the female contributions to male on female domestic violence by saying things that trigger physical events. This area of verbal communication, how female diction changes during stress, is an untapped area of research in psychology.

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