Quick Hits
Daily brief research updates from the cognitive sciences

Yes, you read the headline correctly. Testosterone considered the ultimate male hormone and often associated with aggression has had a bad rap. So, is all of this wrong?

Well, the research into testosterone, for those in the know, never was as clear cut as we often colloquially, and in the popular press, assume. Testosterone is not directly correlated with aggression i.e. more testosterone does not mean you are more aggressive. But we do know that it does make already aggressive men more aggressive. So, it only modulates aggressiveness in certain circumstances.

We also know that it is strongly involved in sexual desire and sports performance. But cuddling – that is new!

So, what did these researchers around Aubrey Kelly at Emory University find?

They investigated behaviours in Mongolian gerbils, that’s actually your common garden gerbil that many of us have owned. Specifically, they looked at male behaviour and in the first experiment they gave male gerbils a shot of testosterone after their partners had become pregnant. Male gerbils can be aggressive in many circumstances such as protecting their territory, but they also form lasting relationships with their partners. This includes cuddling and this cuddling increases when the female is pregnant. Nature’s way of building lasting relationships.

So, what happens when you give these male mice a shot of testosterone when their female mates are pregnant? The researchers expected cuddling to decrease and aggressiveness to increase – not so. Cuddling actually increased!

A further surprise came in a follow up experiment. In this case the female gerbil was then removed from the cage and a new male gerbil put in. In this situation the resident male would normally be aggressive to the “intruder”. However, those that had previously received a shot of testosterone were more friendly to the intruder.

It seems like this previous shot of testosterone had not only made these males cuddlier to their female partners but also more prosocial, friendlier, to strangers. However, in another twist, when these males were given another shot of testosterone their aggressiveness rocketed and they immediately became more aggressive.

“It appears that testosterone enhances context-appropriate behavior. It seems to play a role in amplifying the tendency to be cuddly and protective or aggressive.” Aubrey Kelly

So, it seems that testosterone modulates behaviour in a contextually suitable fashion (and operates with other hormones such as oxytocin which is considered the bonding and cuddle chemical).

Obviously, you will also say that this is only in Mongolian gerbils and not human beings. That is true but a lot of research into animal models of hormones have translated pretty well to human beings – with the caveat that our behaviours are much more complex.

So yes, it seems like testosterone can make men more aggressive, but it can also make men more cuddly. Good to know!

Andy Habermacher

Andy is author of leading brains Review, Neuroleadership, and multiple other books. He has been intensively involved in writing and research into neuroleadership and is considered one of Europe’s leading experts. He is also a well-known public speaker, speaking on the brain and human behaviour.

Andy is also a masters athlete (middle distance running) and competes regularly at international competitions (and holds a few national records in his age category).

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Reference

Aubrey M. Kelly, Jose Antonio Gonzalez Abreu, Richmond R. Thompson.
Beyond sex and aggression: testosterone rapidly matches behavioural responses to social context and tries to predict the future.
Proceedings of the Royal Society B: Biological Sciences, 2022; 289 (1976)
DOI: 10.1098/rspb.2022.0453

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