The role of oxytocin and a related chemical called vasopressin have received increasing attention in scientific circles. Oxytocin is integrally connected with pregnancy, childbirth, lactation, and parenting.

We can speculate that the surges of oxytocin that occur during pregnancy help condition the mother to nurture her baby. Research has linked oxytocin to attachment, so we can assume that increased oxytocin release during pregnancy will enhance the mother-infant bond. It may also contribute to the intense preoccupation with the new baby that mothers develop during pregnancy.

Lack of warmth and affection and poor conflict management in a marriage increase the likelyhood of divorce. it is not so much the amount of conflict that puts a marriage at risk. Rather it is the nature of conflict.

As mentioned above in the section on marriage, a 1993 study of marital interaction by John Gottman found that couples who displayed high levels of defensiveness, contempt, stonewalling, and criticism, as well as facial expressions of disgust were more likely to end up separated or divorced several years later.

the data in the table below is drawn from a 2000 study by Steven Gangestad and colleagues, in which 1.759 men and 2.747 females were rated onthe Kinsey Scale of sexual orientation. As you can see, the vast majority of subjects were rated as exclusively heterosexual, but 15% of men and 22% of women reported some degree of homosexual tendencies. In general, men are more likely to fall at the extreme ends of the scale, while women are more likely to fall in the middle.