# Vestigial behavoirs? **URL:** \ **Category:** Factual Questions\ **Created:** [March 28, 2000, 9:22pm UTC](https://boards.straightdope.com/t/vestigial-behavoirs/9485 "2000-03-28T21:22:00Z")\ **Posts on this page:** 3\ **Page:** 2
**Author:** ![JoeyBlades](https://avatars.discourse-cdn.com/v4/letter/j/a87d85/32.png) [@JoeyBlades](https://boards.straightdope.com/u/JoeyBlades)\ **Post date:** [March 31, 2000, 2:27pm UTC](https://boards.straightdope.com/t/vestigial-behavoirs/9485/21 "2000-03-31T14:27:00Z")
Boris B wrote: > [@](#): > > Man, Cecil is quick! The answer to JoeyBlades’ question… Yeah, that’s actually one of the things that got me thinking about this topic in the first place… Mr.Zambezi wrote: > [@](#): > > The response to nails on a blackboard is thought to be vestigial of the reaction to shrieks. The pitch is similar to a monkey’s warning shreik. That was the other one that got me started on this quest. Sounds like we’re all reading the same articles. I don’t find this one particularly conclusive. Jinx wrote: > [@](#): > > Just for the record, here: The dictionary definition does not discriminate when defining “vestigial”…whether a physical structure (appendix) or a chemical function of the body (at a macrolevel) or the cells (microlevel). Right and I don’t make that distinction either. In fact, I’m trying to ignore both structural and chemical vestiges and see if we can identify one that is purely behavoral. Another thing that comes to mind is fear of heights. I’ve heard that babies have an ingrained, instinctual fear of heights. Maybe this is vestigial in some way. ---
**Author:** ![hardcore](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@hardcore](https://boards.straightdope.com/u/hardcore)\ **Post date:** [March 31, 2000, 3:18pm UTC](https://boards.straightdope.com/t/vestigial-behavoirs/9485/22 "2000-03-31T15:18:00Z")
Another thread [http://boards.straightdope.com/ubb/Forum3/HTML/007069.html](http://boards.straightdope.com/ubb/Forum3/HTML/007069.html) about urinating when terrified may be what you are looking for. This likely evolved to reduce the risk of peritonitis, but is usually just an embarassment now. ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [March 31, 2000, 3:39pm UTC](https://boards.straightdope.com/t/vestigial-behavoirs/9485/23 "2000-03-31T15:39:00Z")
How about fainting in stressful situations? Were some of our ancestors “playing dead”? [Previous page](https://boards.straightdope.com/t/vestigial-behavoirs/9485.md?page=1)