The psychologist Philip Tetlock has argued that the mentality of taboo–the belief that certain ideas are so dangerous that it is sinful even to think them–is not a quirk of Polynesian culture or religious superstition but is ingrained into our moral sense. In 2000, he reported asking university students their opinions of unpopular but defensible proposals, such as allowing people to buy and sell organs or auctioning adoption licenses to the highest-bidding parents. He found that most of his respondents did not even try to refute the proposals but expressed shock and outrage at having been asked to entertain them. They refused to consider positive arguments for the proposals and sought to cleanse themselves by volunteering for campaigns to oppose them. Sound familiar?
The psychology of taboo is not completely irrational. In maintaining our most precious relationships, it is not enough to say and do the right thing. We have to show that our heart is in the right place and that we don’t weigh the costs and benefits of selling out those who trust us. If someone offers to buy your child or your spouse or your vote, the appropriate response is not to think it over or to ask how much. The appropriate response is to refuse even to consider the possibility. Anything less emphatic would betray the awful truth that you don’t understand what it means to be a genuine parent or spouse or citizen. (The logic of taboo underlies the horrific fascination of plots whose protagonists are agonized by unthinkable thoughts, such as Indecent Proposal and Sophie’s Choice.) Sacred and tabooed beliefs also work as membership badges in coalitions. To believe something with a perfect faith, to be incapable of apostasy, is a sign of fidelity to the group and loyalty to the cause. Unfortunately, the psychology of taboo is incompatible with the ideal of scholarship, which is that any idea is worth thinking about, if only to determine whether it is wrong.
in The New Republic