Thanks for pointing this out, Jacques.

I saw something similar on a documentary exploring the nature of 'disgust' where a (a brand-new and sterile) toilet was filled with apple juice. It was explained that it was apple juice and that the toilet was kitchen-clean, and people were offered a drink, serving the juice with a ladle as if from a big punch-bowl. Adults refused, or were very reluctant, but babies and young children were absolutely fine with it.

The same experiment was repeated with a glass of orange juice into which the presenter dipped a (very realistic replica) 'cockroach' - again, the results were the same with toddlers drinking the juice without compunction, but adults refusing.

The point was that disgust - in all its forms, including types of prejudice - is a learned response.

I suppose Duchamp was also dealing with and challenging our preconceptions with his Fountain...