I thought there was some interesting historical data in it:
http://www.salon.com/2015/02/07/the_mysteries_of_chili_heat_why_people_love_the_pain/
http://www.salon.com/2015/02/07/the_mysteries_of_chili_heat_why_people_love_the_pain/
Saturday, Feb 7, 2015 04:00 PM EST
The mysteries of chili heat: Why people love the pain
When eating hot peppers the difference between “just right” and “ouch” is razor-thin. Here's why