Biological roots to domestic violence?

May 2, 2012
© 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

Related Stories

Stress can affect future offspring

August 16, 2011
Rats exposed to stress during early development inherit the effects of that stress to their offspring, largely expressed in behavior impairments but also characteristics of resilience, shows a new study from the University ...

Effects of prenatal stress passed across generations in mice

August 17, 2011
Sons of male mice exposed to prenatal stress are more sensitive to stress as adults, according to a study in the August 17 issue of The Journal of Neuroscience. These findings suggest experiences in the womb can lead to individual ...

Stressed dad = depressed children? Investigating the paternal transmission of stress

August 31, 2011
Does Dad's stress affect his unborn children? According to the results of a new study in Elsevier's Biological Psychiatry, it seems the answer may be "yes, but it's complicated".

Recommended for you

New study rebuts the claim that antidepressants do not work

August 18, 2017
A theory that has gained considerable attention in international media, including Newsweek and the CBS broadcast 60 minutes, suggests that antidepressant drugs such as the SSRIs do not exert any actual antidepressant effect. ...

Should I stay or should I leave? Untangling what goes on when a relationship is being questioned

August 17, 2017
Knowing whether to stay in or leave a romantic relationship is often an agonizing experience and that ambivalence can have negative consequences for health and well-being.

Kids learn moral lessons more effectively from stories with humans than human-like animals

August 17, 2017
A study by researchers at the Ontario Institute for Studies in Education (OISE) at the University of Toronto found that four to six-year-olds shared more after listening to books with human characters than books with anthropomorphic ...

History of stress increases miscarriage risk, says new review

August 17, 2017
A history of exposure to psychological stress can increase the risk of miscarriage by upto 42 per cent, according to a new review.

Study finds children pay close attention to potentially threatening information, avoid eye contact when anxious

August 17, 2017
We spend a lot of time looking at the eyes of others for social cues – it helps us understand a person's emotions, and make decisions about how to respond to them. We also know that adults avoid eye contact when anxious. ...

Communicating in a foreign language takes emotion out of decision making

August 16, 2017
If you could save the lives of five people by pushing another bystander in front of a train to his death, would you do it? And should it make any difference if that choice is presented in a language you speak, but isn't your ...

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Lenfirewood
not rated yet 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.
okyesno
1 / 5 (1) 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.
DaFranker
1 / 5 (1) 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.
Eventide
not rated yet 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.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.