Describing what happens to our brains when we connect with others, Goleman demonstrates how relationships have the power to mold not only human experience but also human biology. In lucid prose he describes from a neurobiological perspective sexual attraction, marriage, parenting, psychopathic behaviors and the group dynamics of teachers and workers. Goleman frames his discussion in a critique of society's creeping disconnection in the age of the iPod, constant digital connectivity and multitasking. Vividly evoking the power of social interaction to influence mood and brain chemistry, Goleman discusses the "toxicity" of insult and unpleasant social experience as he warns of the dangers of self-absorption and poor attention and reveals the positive effects of feel-good neurochemicals that are released in loving relationships and in caregiving.

Broude (psychology, Vassar) has produced a work that is more anthropological than psychological in nature, placing its emphasis on societal and tribal customs rather than on individuals' motivations. Broude uses the concept of sociobiology to explain why so many cultures have similarities in ideals-if not in the way these ideals are carried out. For example, in almost all cultures people will help their own kin before helping strangers, which Broude explains as an instinctive attempt by a person to make sure their genes (some of which are shared by their kin) survive. Similarly, Broude repeatedly explains the differences in male-female sex roles from an evolutionary perspective. Whether or not one agrees that biology is destiny, Broude makes a convincing case in several articles that this is a possible motivation for behaviors that occur across cultures.