Good Fathers - Marmosets

Does having children make men smarter? I know that's not the way it's played out on TV sitcoms, but there is some pretty solid evidence that becoming a dad increases brain power and learning among Marmosets.

Marmosets are small primates found in the jungles of South America. They live in stable, family groups consisting of a monogamously mated pair, offspring and extended family members. When babies are born, it is almost always fraternal twins. The father helps the mother through delivery; he cleans the infants and carries them on his back for their first months of life. When the infants need nursing, he will return them to their mother, and both parents partake in the socially important ritual of grooming their young. When the babies are weaned to solid food, it is the father who feeds them and teaches them where to find a meal.

Scientists were conducting experiments on marmosets to test male testosterone levels when introduced to the scent of ovulating females. In most other primates, male testosterone levels shot up, making them more aggressive and anxious to mate. Not so among marmoset dads. Their testosterone levels remained the same, perhaps because they need to remain available to their mate and committed to the rearing of their children. A subsequent study comparing marmoset fathers with marmosets who had no off-spring found that the dads had better connected neurons and more activity in the prefrontal cortex of their brain. The prefrontal cortex is the part of the brain that allows higher, more complex planning and the ability to handle tasks. According to the scientists, it was not the simple act of fathering a child that caused the increased brain connectivity, but the process of parenting. Marmoset fathers are responsible for over 70% of their offspring's care. Nice to know they've got the brain power to handle it.

Carmen Busko provided our photograph.