“…Specifically, the original research on IQ was based on narrow samples of white, middle and upper class children, to which everyone else was compared (often for the worse; see Fryer Jr & Levitt, 2013 for a review). Such designs (which can also be seen beyond cross-sectional work, of course) reinforced the notion of white middle class children as the 'norm', leading to the perpetuation of racist ideology and practice, along with highly questionable data (e.g., Laundra & Sutton, 2008;Shenk, 2017;Turkheimer, Haley, Waldron, d'Onofrio, & Gottesman, 2003). Given that psychology samples continue to be highly homogenous in terms of race, ethnicity, class, and country of origin (Hartmann et al, 2013;, age norms derived from such cross-sectional studies continue to be, at a minimum, part of the problem of the disregard for explanations of developmental process and, more problematic, part of the perpetuation of inequities in the academy.…”