Pain is emotionally detrimental and consciously avoided; however, it is absolutely crucial for our survival.
Pain perception is one of the most complicated measurable traits because it is an aggregate of several phenotypes associated with peripheral and central nervous system dynamics, stress responsiveness and inflammatory state.
As a complex trait, it is expected to have a polygenic nature shaped by environmental pressures.
References
Diatchenko L, Nackley AG, Tchivileva IE, Shabalina SA, Maixner W. Genetic architecture of human pain perception. Trends Genet. 2007 Dec;23(12):605-13. PMID: 18023497