report higher levels of life satisfaction. Having one or two alleles of the more efficient type raises the average likelihood …

association study. In a nationally-representative twin sample, we first show that about 33% of the variation in life satisfaction … between a functional polymorphism on the serotonin transporter gene (5-HTTLPR) and life satisfaction. We initially find that … individuals with the longer, transcriptionally more efficient variant of this genotype report greater life satisfaction (n=2 …