In case you did not get it from the illustration, I have compared a bell pepper to the Carolina Reaper and the Dragon’s Breath, two very, very, you-do-not-want-it-in-your-taco-hot peppers.
Here is an easy read on bell peppers and their pungency:
You can also find a more complex text about the responsible gene (pun1) here !
Stewart et al. (2005) “The Pun1 gene for pungency in pepper encodes a putative acyltransferase” https://doi.org/10.1111/j.1365-313X.2005.02410.x