Social trust is a heritable trait that has been linked with physical health and longevity. In this study,
we performed genome‑wide association studies of self‑reported social trust in n = 33,882 Danish
blood donors. We observed genome‑wide and local evidence of genetic similarity with other brain‑
related phenotypes and estimated the single nucleotide polymorphism‑based heritability of trust to
be 6% (95% confidence interval = (2.1, 9.9)). In our discovery cohort (n = 25,819), we identified one
significantly associated locus (lead variant: rs12776883) in an intronic enhancer region of PLPP4, a
gene highly expressed in brain, kidneys, and testes. However, we could not replicate the signal in
an independent set of donors who were phenotyped a year later (n = 8063). In the subsequent meta‑
analysis, we found a second significantly associated variant (rs71543507) in an intergenic enhancer
region. Overall, our work confirms that social trust is heritable, and provides an initial look into the
genetic factors that influence it