Researchers examined the effects oxytocin and vasopressin had on perceptions of social dominance. Oxytocin increased perception of greater dominance. Neuroimaging revealed the findings were also reflected in changes in brain regions associated with social perception.
Tilting the head downwards creates an artificial appearance of a facial action that has a strong effect on social perception. Study reveals social judgements about the face are not driven by the face shape or muscularity alone, but by the movement of the head.
Using a combination of movie clips and neuroimaging, researchers find people have positive biases to those they feel are more like them, even if they are unable to see the person's face.