Hmmm… for some reason I’m not terribly surprised by this finding (I wonder why…). Indeed, though, it is a fascinating find! The researchers measured blood testosterone levels and did fMRI scans of the brains of their participants (all men). They also measured the substance – oxytocin. Everyone knows about dopamine and (possibly to a lesser degree) serotonin. Well, oxytocin is one of the lesser known neurotransmitters that also masquerades as a hormone in the body. It is directly involved in the birthing process, lactation, and maternal bonding. It has been labelled the “bonding hormone” (see e.g., http://en.wikipedia.org/wiki/Oxytocin) as it is also implicated in pair-bonding, social recognition, trust, and empathy. As there has recently been much focus on fatherhood research, oxytocin levels have been shown to rise in dads with babies and young children. Thus, oxytocin seems to underlie paternal bonding. It’s a nice read with a very interesting result.