What makes a great dad? According to the fine folks at Emory (a la Fox News, of course):
In a new study published in the Proceedings of the National Academy of Sciences, Mascaro and her team recruited 70 fathers with newborns between the ages of 1 and 2 years old. Both the dads and their children’s biological mothers were asked to complete surveys regarding the fathers’ involvement in hands-on childcare. The study did not receive federal funding.
The researchers then tested the men’s testosterone levels, as lower levels of the sex hormone have been associated with greater parental involvement, according to Medical Daily. The fathers also received MRI scans of their brains to measure activity in the ventral tegmental area (VTA), an area of the brain that governs reward and parental motivation. MRI scans were also done on the men’s testes to measure volume.
The fathers with smaller testicular volume had more brain activity in their VTAs and scored higher on the parenting surveys. Additionally, those with less testosterone had a modest association with better caregiving, a finding the researchers linked with testicle size, since testosterone is produced in the testes.
The media is all over this one because, of course, telling guys that their junk must be small if they take care of their kids is one hell of a headline. I know some men around the blogosphere (there’s four links in there because I am that big a troll) who’d better watch out with their dad bragging, lest the ladies begin to think they’re packing marbles.
Figure 1: The perpetual plight of the SciDad.
That’s some real insightful shit, Marscaro, et al. Should we be surprised it was published in “PNAS”? If you can get access to the manuscript (yeah, yeah, I know. Open Access. #glamgame) it is well worth the read, if only for the chuckle you’ll get from Figure 1. For serious. It’ll be like…
The left panel of Figure 1 compares caregiving relative to the child’s mother with nut size. And this is where this shit is HILARIOUS!!! First, their study has a sample size of 70 dads. Both the mother and the father filled out questionnaires about caregiving and the investigators scored the father’s caregiving so that a score >72 meant they were providing more care than the mother. Want to know how many of these dudes provided at least as much caregiving as the mother?
Six dudes!!! That’s only 9% of the dads!
These guys are setting out to test a hypothesis that parental investment is related to ball volume and they don’t even have a full range of parental involvement represented. Maybe the dads who provide the majority of the care have enormous gonads. Who can be sure?
That’s why so much of this behavior evolutionary neuroscience bullshittery is just that. Bullshittery. As you’ll note (because I’m just going to blog the figure below. Wevs.), like most data in this field, they look like buckshot with some ridiculous, trivial R^2 that comes out pretty because you have convenient data in the extremes. ‘
In their model relating the contribution of testosterone AND testes size, the R^2 is only 0.21. And, testes size only becomes a significant contributor when paternal income and hours worked were removed from the full model.
If there was any doubt in your mind why I think brain research is largely bullshit, this should clear it up good and fast. Let us all now return to our lamentations over the decline of American masculinity.