Here's a scientific study that might send a bout of collective laughter across humanity.
Followed by some obscure measuring.
And as much as I'd like to type just about anything else, CNN has deemed me the one to share this with you. So, here goes.
A new study suggests that dads with smaller testicles are more likely to be nurturing to their infants.
It was published Monday in the Proceedings of the National Academy of Sciences, which goes by the acronym PNAS (Yes, that's chuckle-worthy in this context, so go ahead and laugh).
Researchers at Emory University used an MRI to measure the gonads of 70 lucky biological fathers, age 21 to 43, in the Atlanta area. (Yes, they got paid for this.)
The scientists also studied each dad's brain pattern as he viewed photos of his child, a stranger's child or an adult stranger.
They were looking for activity in a part of the brain believed to be "involved in the motivation to approach and nurture offspring," said Emory anthropologist James Rilling, one of the study authors.
Meanwhile, the men's partners answered questions about how involved they were in taking care of their infant children. Do they take them to doctor visits or put them to bed?
The researchers then crunched -- sorry, bad choice of verbs -- the data.
"Fathers' testicular volume and testosterone levels were inversely related to parental investment," the study says, "and testes volume was inversely correlated with nurturing-related brain activity when viewing pictures of their own child."
When I learned of this study, I immediately feared what could happen if it gets taken out of context.
Dystopian future headline: "Deadbeat Dads Blame it on Large Family Jewels!"
Dystopian future advice mothers give to daughters before marriage: "But will he be a good father? Weigh the wedding tackle!"
So, before anyone launches such a premature declaration, know that these researchers don't claim that the size of a dude's genitals determines how good a father he'll be. And a pair of testes experts we asked to review the study point to caveats as big as a couple of boulders.
Researcher: Caregiving could lead to shrinkage
The study started off with a pretty simple idea. Animals have to divide time between mating and parenting. Some previous studies suggested that less testosterone leads to less mating and therefore more time and and energy spent parenting.
So this team wondered -- quite possibly listening to the Bloodhound Gang -- whether there's a similar tradeoff for humans.
The correlation they found suggests that there is "a tradeoff between mating effort and parenting effort," they say in their study.
Not so fast, says Lee Gettler, an anthropologist at Notre Dame who has conducted research on how men respond physically to father-child interactions.
To make the suggestion behind this study work, bigger privates would have to relate to more "mating" by men. But they don't, he says. "Large testes do not make you act promiscuously or badly as a parent."
Also, "testes size doesn't matter all that much for testosterone production."
For the record, size also doesn't determine how much sperm is being created, says Abass Alavi, researcher with the University of Pennsylvania