Study Finds Penis Size Affects Attractiveness and Rival Threat

A new study has found that penis size influences women's perceptions of male sexual attractiveness and men's assessments of rivals as threats, providing experimental evidence on an aspect of human evolution that has long intrigued scientists.

Researchers at the University of Western Australia, led by evolutionary biologist Dr. Upama Aich, examined how physical traits affect mate choice and competition among more than 600 men and 200 women. Participants rated computer-generated male figures that varied in height, body shape, and penis size. Women evaluated the figures for sexual attractiveness, while men assessed them for intimidation as potential fighting opponents and sexual rivals. Some viewed life-sized images in person, others used scaled versions in an online survey. Each figure rotated slightly to allow full observation.

The results, published in the journal PLOS Biology, showed that women rated taller men with a higher shoulder-to-hip ratio, indicating a V-shaped torso, and larger penises as more attractive. However, benefits plateaued beyond certain thresholds; further increases in these traits yielded diminishing gains. Height and body shape exerted the strongest...