The brain sees monogamy as a reward
A new study of prairie voles, one of the few other mammals that choose just one mate, seems to indicate that the brain's reward system is hard-wired to respond to these bonds.
Scientists have long known that socially monogamous mammals, including humans, actually change their perception of their partners when they bond as adults. What they didn't know was how the brain's neural circuitry is activated by these social interactions. This is the first comprehensive look at that question and it turns out a neural pathway that responds to rewards can be activated to increase a partner's preference for partners over strangers.