Are various ethics irrational? Quite probably.
Being more specific on which ethics you mean might give more to chew on.
Humans are notoriously great at pattern matching, and seeing things that aren't there simply based on a prior mental model. Stereotypes of all kinds are a result of this.
Humans are notoriously great at pattern matching, and seeing things that aren't there simply based on a prior mental model. Stereotypes of all kinds are a result of this.