Tragically there have been so many instances over the years I've come to the conclusion it's part of the Human condition - even a good education doesn't eradicate it (although it helps).

Take the classic example, just look at how completely bonkers millions of intelligent Germans went during the 1930s.

The condition I'm afraid is incurable. What's even worse is that it seems that under the right circumstances anyone can catch it.

aka "let's play God and see what happens"