We’ve written previously that fatherhood is associated with decreased levels of testosterone in dads (except for when a testosterone boost might come in handy). For the most part, the general belief has been that the dads’ lower testosterone limits their impulses to mate (presumably not with their baby-momma), thus keeping them invested in their children.
Some recent research from Emory University, however, suggests another, or additional, possibility.1 Specifically, the researchers compared the testosterone and oxytocin hormone levels of a group of fathers of 1-2 year old children with hormone levels of men without children. In addition to collecting blood samples to measure the hormones, the researchers also scanned the brains (via MRI scans) of all the men while they were looking at 3 types of pictures: 1) children’s faces (of the same sex and age as their own kids, and depicting a range of emotional expressions), 2) unknown adult faces displaying similar emotions, and 3) scantily clad women. The research team was interested in whether fathers vs. non-fathers responded neurologically (i.e., as assessed via increased brain activation) to the different types of images and, if so, what role hormones play in those neural responses.