High Quality Content by WIKIPEDIA articles! In genetics rs6311 is a gene variation—a single nucleotide polymorphism (SNP)—in the human HTR2A gene that codes for the 5-HT2A receptor. 5-HT2A is neuroreceptor, and several scientific studies have investigated the effect of the genetic variation on personality, e.g., personality traits measured with the Temperament and Character Inventory or with a psychological task measuring impulsive behavior. The SNP has also been investigated in rheumatology studies.