Since most of the Sapolsky videos on here are long, I thought I would post a shorter one to draw people's attention to an amazing scientist. In this video he brielfy touches on why stress in our lives caused by any number of psychological reasons (public speaking, driving, dating) gives us diarrhea, dry mouth, loss of appetite, etc. If you find this topic interesting, check out his book "Why zebras don't get ulcers." It's an excellent work which is written in a very understandable fashion for such a complex topic. If you're more interested in his field work and the kind of shenanigans involved in collecting blood samples from wild baboons in Africa (without them knowing) check out his book "A primate's memoir" which remains one of the funniest books I've ever read. I read it twice in a row while living in a tent in some mountains of arctic Alaska for 6 weeks.