Why do we think some things are tasty and others are disgusting? This question has not been answered by any of the physical, social, or biosciences. I will illustrate this point with some examples from my cross-cultural research on the desirability and edibility of different kinds of fish. Eels and carp were once considered delicacies in the United States of America, but today they are considered disgusting and are not eaten. Why? This question becomes important when we think about the environmental consequences of eating some fish and not others.