costs of individual foraging challenges. Meerkats teach their young how to hunt dangerous but energy- rich scorpion prey, providing an education that bypasses the risks of trial and error learning. Humans unconsciously wrinkle their noses and pull back their lips into an expression of disgust that communicates information about disease-ridden and toxic substances, thereby lowering the costs of sickness to others who might be exposed. Each of these specializations involve exquisitely designed neural circuits and sensory machinery. Each specialization is used for one and only one problem — except in humans. Animal thoughts and emotions are like monogamous relationships, myopically and faithfully focused on a single problem for life. Human thoughts and emotions are like promiscuous relationships, broad-minded and liberated, free to couple as new problems surface. Unlike any other animal, the thoughts and emotions we use to solve problems in one domain can readily be combined and recombined with thoughts and emotions from other domains. This is powerful, providing great flexibility in addressing novel problems, some of which we create for ourselves. Disgust provides an example. Disgust originally evolved as an adaptive response to detecting substances that are toxic to our health, especially substances that are outside of the body but should be inside: feces, urine, blood, and vomit. Within the circulation of a promiscuous brain, however, disgust journeys to distant problems, including the moral attitude of vegetarians toward meat eaters, our revulsion toward incest, and abhorrence of gratuitous torture. This journey involves the same brain mechanism that serves original disgust, together with new connections that give voice to our moral sense. Promiscuity enables creativity. What the sciences reveal is that the capacity for promiscuous thinking was realized by evolutionary changes in the number of newly wired up brain areas. By increasing these connections, it was po