Publication Date




Embargo Period


Degree Type


Degree Name

Doctor of Philosophy (PHD)


Psychology (Arts and Sciences)

Date of Defense


First Committee Member

Debra Lieberman

Second Committee Member

Michael McCullough

Third Committee Member

Elizabeth Losin

Fourth Committee Member

Soyeon Ahn

Fifth Committee Member

Casey Klofstad


Recent psychological research supports the existence of a suite of cognitive adaptations that function to detect alliances. This mechanism (1) monitors the social environment for cues that sets of individuals are predisposed to affiliate with one another, (2) categorizes these individuals as members of the same coalition, and (3) uses these categories to guide behavior. Empirical tests of the alliance detection hypothesis support a key claim that racial categorization, long believed to be stable and inflexible, is a by-product of the alliance detection mechanism, such that categorization by race is reduced in the presence of coalitional cues uncorrelated with race. Empirical tests also suggest that three contextual factors activate the alliance detection system: direct conflict; overt cooperation; and shared political beliefs. It remains unclear whether additional contexts similarly prompt categorization by coalition, as well as which cues of shared beliefs are necessary to activate the psychology of alliance detection. The current set of studies extended prior research by examining shared beliefs in a novel domain, religion. Two preregistered experiments using the “Who Said What?” paradigm tested 1) whether expressed religious beliefs prompt social categorization; 2) whether shared religious beliefs specifically activate the alliance detection system, as evidenced by the down-regulation of racial categorization but not of sexual categorization; and 3) whether the strength of a person’s own religious belief or religious identity influences how strongly that person categorizes others by religious belief. Results provided strong evidence for social categorization based upon shared religious beliefs, and partial support for the hypothesis that shared religious beliefs activate the alliance detection mechanism. Findings were mixed regarding a relationship of religious belief or of religious identity with categorization by religion.


alliance detection; Who Said What paradigm; social categorization; coalitional psychology; evolutionary psychology; religion

Available for download on Thursday, April 22, 2021