Infidelity

BP Zietsch, a psychologist in Queensland, Australia, has a theory to explain why some people are more likely to practice infidelity than others.

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There are plenty of social as well as biochemical factors that account for infidelity in human relationships, and they are all too familiar to story-tellers and historians.

Zietsch thinks there may also be a link between promiscuity and specific variants of vasopressin (below, left) and oxytocin (below, right) receptor genes.

220px-Vasopressin_labeled    250px-Oxytocin_with_labels

Vasopressin is a hormone that has powerful effects on social behaviors like trust, empathy and sexual bonding in humans and other animals. Mutations in the vasopressin receptor gene may change human sexual behaviour.