“…Since this original report, others have confirmed the association between the 5-HTTLPR short allele and heightened anxiety (Du, Bakish, & Hrdina, 2000;Katsuragi et al, 1999;Mazzanti et al, 1998;Melke et al, 2001;Munafo, Clark, & Flint, 2005;Schinka, Busch, & Robichaux-Keene, 2004;Sen, Burmeister, & Ghosh, 2004) and have also demonstrated that individuals possessing the short allele more readily acquire conditioned fear responses (Garpenstrand, Annas, Ekblom, Oreland, & Fredrikson, 2001) and develop affective illness (Lesch & Mössner, 1998), in comparison with individuals homozygous for the long allele. Infants homozygous for the S allele have similar increases in anxiety-related measures (Auerbach, Faroy, Ebstein, Kahana, & Levine, 2001;Auerbach et al, 1999).…”