Unconstrained descriptions of Facebook profile pictures support high-dimensional models of impression formation

Dominant models of impression formation focus on two fundamental dimensions: a horizontal dimension of warmth/communion/trustworthiness and a vertical dimension of competence/agency/dominance. However, these models have typically been studied using theory-driven methods and stimuli of restricted complexity. We used a data-driven approach and naturalistic stimuli to explore the latent dimensions underlying >300,000 unconstrained linguistic descriptions of 1000 Facebook profile pictures from 2,188 participants. Via traditional (Exploratory Factor Analysis) and modern (natural language dictionaries, semantic sentence embeddings) approaches, we observed impressions to form with regard to the horizontal and vertical dimensions and their respective facets of sociability/morality and ability/assertiveness, plus the key demographic variables of gender, age, and race. However, we also observed impressions to form along numerous further dimensions, including adventurousness, conservatism, fitness, non-conformity, and stylishness. These results serve to emphasize the importance of high-dimensional models of impression formation, and help to clarify the content dimensions underlying unconstrained descriptions of individuals.