For our GWAS of adventurousness, we analyzed data from a sample of research participants from 23andMe (n = 557,923). We analyzed responses to the question: “If forced to choose, would you consider yourself to be more cautious or more adventurous?”, with possible responses ranging from “[1] Very cautious” to “[5] Very adventurous.” For our GWAS of three of the four risky behaviors—automobile speeding propensity (n = 404,291), drinks per week (n = 414,343), and number of sexual partners (n = 370,711)—and for the first principal component (PC) of the four risky behaviors (n = 315,894), we analyzed UKB data. For the remaining risky behavior, ever smoker (n = 518,633), we meta-analyzed GWAS results from the UKB and from the TAG Consortium44. Our automobile speeding propensity phenotype is based on responses to the question: “How often do you drive faster than the speed limit on the motorway?”, with possible responses ranging from “[1] Never/rarely” to “[4] Most of the time.” We dropped individuals who answered “[5] Do not drive on the motorway,” and then we normalized the categorical variable for males
