Yes I think you should. Do you have Dawkins’ book? Or is that just a quote someone gave you? I looked up the quote, I read the book 10 years ago and had forgotten the details. Dawkins points out that one I.J. Good discussed this in Nature, 375, 541: The title is “When a batterer turns a murderer”.

I think that you should have been given Dawkins’ entire discussion if this is going to be a meaningful probability exercise.