[If] personality traits have a significant genetic contribution (which seems clear) then we can ask – to what extent do personality traits go along with physical characteristics? This is plausible because sometimes a single gene will code for a protein or enzyme that has multiple functions, and therefore could (for example) affect the development of both the brain and the face.
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The arrow of cause and effect may also go the other way. People who look a certain way may have a particular life experience that contributes to certain personality traits. A baseline aloof expression may, for example, contribute to introversion.
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[One] study was done in a sample of 12 thousand volunteers who completed a self-report questionnaire measuring personality traits based on the “Big Five” model and uploaded a total of 31 thousand ‘selfies’.
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What they found was that the trained neural network AI was able to predict the relative personality trait of two randomly chosen individuals based on photographs with a 58% accuracy, where chance guessing would result in 50%. So in other words, the AI had pictures of two individuals and had to guess which one was more agreeable, or more neurotic. These results are spectacularly unimpressive.
