Is it OK for a brother and a sister to have sex? What if she is on birth control and he uses a condom? What if they develop a deeper connection as a result? In a study by Dr. Jonathan Haidt most people thought this was wrong but couldn’t come up with a good reason.
Counter-intuitively, this is how moral and aesthetic judgement generally works; we have an automatic reaction to something or someone and then immediately begin to generate reasons to justify our initial assessment in a process known as confabulation.
In the present example, evolution has favored organisms with an aversion to incest because individuals who mated with siblings were less likely to successfully pass on their genes than those endowed with a sexual preference for non-kin. This seems to have led to a natural tendency to feel disgust at the thought of a brother and sister having intercourse. Haidt’s work suggests all rationale for these feelings is entirely post-hoc.
What is something or someone you tend to have a knee-jerk negative reaction to? Why do you have this reaction? Is it possible that there really is no good reason?
Andy's Quote of the Day 