Brain researchers are finding the sources of our nastiest temptations.
Why does being bad feel so good?
The most enjoyable sins engage the brain’s reward circuitry, including evolutionarily ancient regions such as the nucleus accumbens and hypothalamus; located deep in the brain, they provide us such fundamental feelings as pain, pleasure, reward, and punishment. More disagreeable forms of sin such as wrath and envy enlist the dorsal anterior cingulate cortex. This area, buried in the front of the brain, is often called the brain’s conflict detector, coming online when you are confronted with contradictory information or even simply when you feel pain. The more social sins (pride, envy, lust, wrath) recruit the medial prefrontal cortex. Found just behind the forehead, this region helps shape the awareness of self.
It might be too strong to claim that evolution has wired us for sin, but excessive indulgence in lust or greed could certainly put you ahead of your competitors. “Many of these sins you could think of as virtues taken to the extreme,” says Adam Safron, a research consultant at Northwestern University whose neuroimaging studies focus on sexual behavior. “From the perspective of natural selection, you want the organism to eat, to procreate, so you make them rewarding. But there’s a potential for that process to go beyond the bounds.”