Recently a new study was published by the the Proceedings of the National Academy of Sciences (PNAS—just pronounce it slowly in your head) suggests that there might be a correlation between the size of a man’s testicles and how involved he is in parenting.
Anthropologists from Emory University in Atlanta wanted to try to better understand why some men are more actively engaged in child rearing than others, said study lead author James Rilling.
“We know children with involved fathers — at least in modern western societies — have better developmental outcomes socially, psychologically, and educationally. Yet, some men choose not to be involved,” he said.
So they went balls to the walls and started from the beginning, the testes.
The study involved 70 men who lived with their partners and were fathers to children aged between one and two. They were asked about details of their parenting as well being analyized for brain activity when shown photographs of their children
According to their study, men with larger testes are significantly less likely to display good parenting skills compared to men with smaller testes because of a well-established trade-off in evolution between mating and child-rearing, scientists said. Larger testes are linked with higher testosterone levels and sperm counts, as well as increased promiscuity and, in humans, marital breakdown and divorce, the researchers said.
Rilling and his colleagues took blood tests at the start of the study to measure the men’s testosterone levels. They also conducted interviews with the fathers and mothers separately about how involved their partner was with their child: how often did they change diapers, feed and bathe their little one, prepare a meal, take the child to the doctor?
“We relied on the mothers’ reports because we thought that would be less biased,” said Rilling, an associate professor of anthropology, psychiatry, and behavioral sciences.
The researchers also measured each man’s brain activity using functional magnetic resonance imaging (fMRI) while the fathers viewed photos of their children with various expressions: happy, sad and neutral. A structural MRI was also used to measure the size of each man’s testicles.
The findings, Rilling said, suggest that “men with smaller testes and lower testosterone levels were more involved in care-giving. The men with smaller testes volume also had a stronger neural response — the fMRI showed more activity in the ventral tegmental area, a reward center of the brain — when the men viewed images of their children.”
The researchers concluded that while the new findings suggest there’s a link between testes size and a man’s involvement with his kids, anatomy isn’t a sure predictor of a male’s parenting potential.
“It could also be that when men become more involved as caregivers, their testes shrink,” he added.
Gone are the days of being concerned about penis size, the real issue could be the size of a man testicles. Side note, never Google image search the word “testicle”.