Men with high testosterone levels are more likely to have multiple wives, according to a new study.
They also give less attention to their kids.
High testosterone levels have been linked to increased sexual activity, infidelity and marital conflict. However, after men become fathers, their bodies typically pump out less of the hormone.
In the study involving rural Senegalese villagers, the researchers underscored testosterone's critical role in a mating and parenting.
Lead researcher Alexandra Alvergne, an anthropologist at the University of Montpellier, France, and the University of Sheffield, UK measured testosterone levels in 21 polygynous fathers as well as 32 monogamous dads and 28 unmarried men without children.
The researchers also asked the men's wives about the time and money their husband spent to the family.
The findings revealed that no matter how many wives they had, fathers had lower testosterone levels than single men, on average.
It also showed that among fathers, those with more testosterone tended to invest less time in their wives and children.
And polygynous men under the age of 50 produced more testosterone than monogamous men, on average.
According to Alvergne, older men with more than one wife made less of the sex hormone than other men. While older men may make less testosterone, they typically enjoy more prestige in their villages, which could make it easier to find multiple wives.
The study appears in journal Hormones and Behavior.