This may provoke recognition in many parents: a researcher into OCD (obsessive-compulsive disorder) was looking for the involvement of a neurotransmitter; he came up empty in his search, but in a what-the-hell spirit he sent off his samples to be analyzed for less well-known chemicals -- and found to his astonishment that sufferers of OCD were showing very high levels of oxytocin, the famous "pair-bonding" hormone. On reflection, however, he realized that the behavior of new or expectant parents often resembled OCD, and if you think about it, people "in love" are of course famous for obsessive behavior. So he's suggesting that OCD is a dysfunctional variant of something that is in fact adaptive and normal.