... This flaw reflects the fallacy that researchers believe they can safely ignore the degree to which the stimuli used in experimental studies match the distributional properties of the real-world groups they represent. One reason for this disregard may be the belief that all groups have roughly identical distributions on important underlying causal characteristics. 1 Yet this assumption is incorrect, as groups differ (and often markedly so) on important personality, motivational, and cognitive dimensionsin other words, on the interest and ability factors that relate to nearly all outcomes (see, e.g., ACT, 2017;Andreoni et al., 2019;Beaver et al., 2013;Benbow & Stanley, 1980;Benbow, Lubinski, Shea, & Eftekhari-Sanjani, 2000;Byrnes, Miller, & Schafer, 1999;Ceci & Williams, 2010;Diekman, Steinberg, Brown, Belanger, & Clark, 2017;Gottfredson, 1998;Halpern et al., 2007;Hsia, 1988;Hsin & Xie, 2014;Jussim, Cain, Crawford, Harber, & Cohen, 2009;Jussim, Crawford, Anglin, Chambers, et al., 2015a;Jussim, Crawford, & Rubinstein, 2015c;Lee & Ashton, 2020;Lippa, 1998;Lu, Nisbett, & Morris, 2020;Lubinski & Benbow, 1992;Lynn, 2004;Lynn & Irwing, 2004;McLanahan & Percheski, 2008;Roth, Bevier, Bobko, Switzer, & Tyler, 2001;Sowell, 2005Sowell, , 2008Su, Rounds, & Armstrong, 2009;Tregle, Nix, & Alpert, 2019;Wright, Morgan, Coyne, Beaver, & Barnes, 2014). 2 In understanding the role of decision-maker bias in producing disparate outcomes, it is necessary to compare and interpret the size of categorical bias effects with the size of these behavioral differences across groups. ...