Testosterone not guilty
(well, not quite)

Aggressive loutish lads are often considered to be ‘testosterone fuelled’. More testosterone means increased, unfocused aggression; less of it means calm and controlled behaviour. Or does it?

The link between aggressive behaviour and the group of hormones commonly referred to as testosterone is more tenuous and certainly more complex than many scientists would have you think.

castration?

Undoubtedly, there does appear to be a link between aggression and testosterone, and indeed, if the source of the latter is removed (say by castration), levels of the former are often seen to drop. But increase levels, and initially there is no observable change. In fact, it takes a massive increase to more than double normal levels to effect any noticeable response.

Most importantly, even when aggression levels are increased, it is not random and flying out wildly, but channelled down the socially prescribed paths that are available. In a hierarchical primate society, a male primate with suddenly massively increased levels of testosterone coursing through its body would not go on a random attack, it would still treat higher ranking primates with due respect, but would become a complete sod to lower ranking primates.

Basically, testosterone facilitates increased levels of brain activity, but not that associated with aggressive behaviour. The cause of aggression is not simply the presence of testosterone, but its interaction with other biological processes, and particularly, the social environment.

loutish females?

In spotted hyenas in Kenya, females apparently have a lot more of a testosterone related hormone than males. Females are larger, with greater musculature, and tend to be socially dominant. In a colony that has been transplanted to California, the physically identical females have similarly high levels of the hormone and are similarly larger and more muscular than their male counterparts. However, the level of social domination has been considerably delayed in the captive, controlled, California colony. A large element of the learnt ‘wild’ behaviour was lost.

social insecurity

There are clear signs, then, that there is a balance between the environment and biology. Certainly, it is not a straightforward case of biological determinism (the idea that ‘physical biology explains all’).

Dodgy scientists, money grabbers and politicians can be relied on to bend the truth to suit their own perverse ends. But however much ‘socio-biology’, ‘neurology’ and ‘genetics’ research is done, there is little chance of a fresh outbreak of the biological determinist picture they try to paint.

In reality, biology (through the existence of life) provides potential, and the environment shapes this potential. Aggressive behaviour is shaped by a flawed social system, such as this one we live in. Creating a better environment, physical and social, is the only way to fundamentally alter this cycle of aggression. And by the way, you only get research into ethically dubious areas when you live in an ethically dubious society.