@duanemanscill
Humans feel jealousy due to evolutionary adaptation: it motivates mate guarding, resource competition, and self-improvement to boost survival and reproduction chances.
pmc.ncbi.nlm.nih.gov
https://pmc.ncbi.nlm.nih.gov/articles/PMC5609545/
https://www.sciencefocus.com/the-human-body/where-does-jealousy-come-from