Big Five personality

The Big Five (also called OCEAN or the five-factor model) is the dominant taxonomy of personality in academic psychology. The five domains — Openness to Experience, Conscientiousness, Extraversion, Agreeableness, and Neuroticism — emerged from decades of factor analysis on personality language across dozens of cultures and languages.

Each domain breaks down into six narrower facets, giving 30 total facets. Openness, for example, includes Imagination, Artistic Interests, Emotionality, Adventurousness, Intellect, and Liberalism. Two people can both score "high on Openness" while being totally different on the underlying facets — which is why facet-level scoring matters for friend matching.

Are We Friends? scores every member on the IPIP-NEO-120, a 120-item public-domain Big Five instrument. Compatibility ranking happens on the full 30-facet vector, not just the five domain averages. That's the difference between "we both like art" (domain match) and "we both score high on Imagination AND Intellect AND Adventurousness" (facet match).