Nosek & Smyth (2007): A multitrait-multimethod validation of the Implicit Association Test: Implicit and explicit attitudes are related but distinct constructs.

We applied Campbell and Fiske’s (1959) classic multitrait-multimethod design precepts to test the construct validity of implicit attitudes as measured by the Implicit Association Test (IAT). Participants (N = 287) were measured on both self-report and IAT for up to seven attitude domains.

Through a sequence of latent-variable structural models, systematic method variance was distinguished from attitude variance, and a correlated two-factors-per-attitude model (implicit and explicit factors) was superior to a single-factor-per-attitude specification. That is, despite sometimes strong relations between implicit and explicit attitude factors, collapsing their indicators into a single attitude factor resulted in relatively inferior model fit.We conclude that these implicit and explicit measures assess related but distinct attitude constructs.