“…Previous studies have found associations between the Met66 allele and increased introversion (Terracciano et al, 2010), harm avoidance (Montag, Basten, Stelzel, Fiebach, & Reuter, 2010), tendency to ruminate (Beevers, Wells, & McGeary, 2009), lower levels of conscientiousness (Hiio et al, 2011), an increased vulnerability to stress (Casey et al, 2009), increased anxiety-related behaviours (Chen et al, 2006) and increased risk of an anxiety disorder in children and adolescents (Tocchetto et al, 2011). In contrast, other studies have reported an association between the Val66 allele and higher neuroticism scores, as well as increased risk of anxiety symptoms during adolescence (Chen, Yu, Liu, Zhang, & Zhang, 2015; Frustaci et al, 2008).…”