A new study conducted by English researchers shows that a man’s testosterone levels, his height, and the age of puberty are not determined by genetics, but rather by where he would have spent his childhood.
Testosterone is the male hormone that triggers puberty, develops muscle mass and contributes to the growth of the child. A new study by researchers at the University of Durham, England, suggests that testosterone levels would be governed by the environment in which a man spends his childhood. The work of this research team was published in the journal Nature Ecology & Evolution.
The scientists compared 5 groups of different men:
– those born in Bangladesh who still live there
– those born in Bangladesh, but who moved to London as children
– those born in Bangladesh who moved to London as an adult
– those born in the United Kingdom but whose parents come from Bangladesh
– and finally, those born in the United Kingdom and whose ancestors are European
In total, the testosterone level, the height and the age at which puberty started, were measured in 359 men.
Variations according to the country of childhood
Surprisingly, the researchers found significant differences between populations. Men born in the United Kingdom or Bangladesh, but who were raised in the UK, seemed, on average, to share similarities in their testosterone levels, height and age at which they had entered puberty, regardless of their ancestry. Men born and raised in Bangladesh – including those who emigrated to the UK as adults – were found to enter puberty later, be smaller and have lower testosterone levels. According to the researchers, this shows that something happens during childhood, linked to the environment, and has long-term effects on testosterone production.