Other phobias that persist intomodern times may have been fixed much more recently than snakes and spiders, say in the late Paleolithic age, about 100, 000 years ago, or even morerecently.

For example, if you have a phobia of spiders (as millions of people do), you only feel anxious when there's a spider around, otherwise you feel fine.

People with body dysmorphic disorder spend at least an hour a day, sometimes much longer, thinking about that imperfection.