Figure 3.

DRD4 genotype and self-reported activity. The number of hours per day of activity reported in 1981 is plotted versus participants with a DRD4 7R/x genotype (black bars) or non-DRD4 7R/x genotype (striped bars). Comparisons are shown at the 5th, 25th, 50th, 75th, and 95th percentiles. Including DRD4 2R/x and 3R/x individuals with the DRD4 7R/x individuals instead of the non-7R/x individuals (Ding et al., 2002; Grady et al., 2003; Wang et al., 2004; Grady et al., 2005) gave comparable activity level differences (i.e., an ancestral 4R/4R vs non-4R/4R division).