The frequency of smiles is greater in women than in men. Women are also expected to smile more often than men. Studies have found that low rates of smiling lead to more negative evaluations of women than of men. Men's smiles are also taken to be more indicative of their personality traits than women's, perhaps because of their relative rarity in men. Men's positive expressions are also perceived as more intense than women's, even when objective intensity is held constant.
Briton & Hall, 1995
Deutsch, LeBaron, & Fryer, 1987
Hall, Carney, & Murphy, 2002
Hess, Adams, & Kleck, 2004, 2005
Hess, Blairy, & Kleck, 2000a
LeFrance, Hecht, & Levy Paluck, 2003
Krumhuber, Manstead, Kappas, 2007