Women find happy guys significantly less sexually attractive than swaggering or brooding men. A University of British Columbia study found dramatic gender differences in how men and women rank the sexual attractiveness of non-verbal expressions of commonly displayed emotions, including happiness, pride, and shame.
Women were least attracted to smiling, happy men, preferring those who looked proud and powerful or moody and ashamed. In contrast, male participants were most sexually attracted to women who looked happy, and least attracted to women who appeared proud and confident.
Read more at University of British Columbia