The rigidity-of-the-right hypothesis (RRH), which posits that cognitive, motivational, and ideological rigidity resonate with political conservatism, is an influential but controversial psychological account of political ideology. Here, we leverage several methodological and theoretical sources of this controversy to conduct an extensive quantitative review—with the dual aims of probing the RRH’s basic assumptions and parsing the RRH literature’s heterogeneity. Using multi-level meta-analyses of relations between varieties of rigidity and ideology measures alongside a bevy of potential moderators (s = 329, k = 708, N = 187,612), we find that associations between conservatism and rigidity are tremendously heterogeneous, suggesting a complex—yet conceptually fertile—network of relations between these constructs. Most notably, whereas social conservatism was robustly associated with rigidity, associations between economic conservatism and rigidity indicators were inconsistent, small, and not statistically significant outside of the United States. Moderator analyses revealed that non-representative sampling, criterion contamination, and disproportionate use of American samples have yielded over-estimates of associations between rigidity-related constructs and conservatism in past research. We resolve that drilling into this complexity, thereby moving beyond the question of if conservatives are essentially rigid to when and why they might or might not be, will help provide a more realistic account of the psychological underpinnings of political ideology.