The Reversal of Spearman’s Hypothesis in Incarcerated Populations and the Role of Non-Shared Environmentality

White-Black (W-B) cognitive performance differences tend to be more pronounced on more g -loaded subtests, a phenomenon posited by, and sometimes denoted by the term, Spearman’s Hypothesis (SH). But SH might not be confirmed in all circumstances. The current study aims to investigate particular conditions under which it might fail. Exploratory factor analysis employing vectors of subtest-level effects as the unit of analysis is used to examine the relationships between non-shared environmentality ( e 2 ), g and culture loadings, and W-B differences in two incarcerated and three normative samples, all evaluated using Wechsler series cognitive tests. Parallel analysis recommended a two-factor solution. Factor 1 was associated with negative clustering for the g and culture loading vectors, but positive clustering for both the incarcerated W-B difference and e 2 vectors. The three normative W-B difference vectors clustered with respect to Factor 2 onto which the g and culture loading vectors also weakly, but positively, cross-loaded. These results suggest that when racialized sources of environmental harshness are high (such as in incarceration settings) SH reverses, with e 2 variance (which captures environmental harshness) and non- g sources of performance variance being generative of these group differences.