haloperidol — a DRD2 dopamine antagonist — helps control aggression in psychotic patients. Guo found

haloperidol — a DRD2 dopamine antagonist — helps control aggression in psychotic patients. Guo found that levels of violence were about twice as high for one variant of the DRD2 gene than others, and about 20% higher for a particular variant of the DAT1 gene. These genetic variants cause differences in dopamine, which cause differences in expected and experienced reward, which cause differences in perceived risk, which cause differences in the odds of getting in a fight and harming others. These are not genes for aggression, violence or evil. There are no such genes. Rather, they are genes that change our perception of risk. Because risk is related to all sorts of decisions, these genes can affect the odds that we directly harm others. They are part of the story of individual differences, and part of the story of why some are more likely to engage in evildoing. Everything I have discussed thus far focuses on actions, on how the psychology of desire and denial combine to fuel behaviors that lead, directly or indirectly, to excessive harms. I have also explained how different biological ingredients predispose us toward different degrees of self-control, and thus, differences in our ability to omit particular actions. This sense of omission is a virtue, a sign of resisting temptation. But can omissions be a sign of vice, of resisting an action that is called for? Can omissions ever reach such a scale that we would consider individuals or societies as evil omitters? The sin of sloth. What’s worse: 1) giving a lethal overdose to someone suffering from an incurable disease or allowing this person to die by removing life support? 2) pushing someone in front of a runaway truck to stop the truck and save the lives of five others or allowing someone to walk in front of the truck instead of warning them? 3) pouring a toxic chemical into your competitor’s drink in order to make him sick or allowing your competitor to drink the toxic chemical that was placed on the table by someone else? Even though all of these situations seem quite bad, most people have a gut feeling that the actions are worse than the omissions. They also feel that when we omit life support, fail to warn someone of a runaway truck, or remain silent about a toxic drink, that we are less responsible for the consequences that unfold. Dozens of studies, using hundreds of different examples, and thousands of subjects, support what our gut expresses: we are captive to an omission effect. Even when we understand that the consequences are precisely the same — the suffering patient dies, the truck kills the person, the toxic chemical makes the competitor sick — and so too are the person’s goals and intentions — eliminate suffering, save five people, take out the competitor — we are seduced to believe that action is worse than omission or that doing harm to another is worse than allowing harm to occur. The omission effect lays bare a tension between unconscious, spontaneous intuition and conscious, reflective thought. On the one hand, there are potentially good reasons why we evolved this Hauser Chapter 4. Wicked in waiting 136 HOUSE_OVERSIGHT_012882