Individual study overall Autism-Spectrum Quotient (AQ) means for nonclinical populations. Bars indicate confidence intervals, point size scaled to the number of individuals in each study. Studies are ordered chronologically. From 2001 to 2011, the unweighted mean AQ score = 15.27 (SD = 1.73); from 2012 to 2014, m = 15.37 (SD = 2.12). Overall mean is indicated by the dotted line.