Size does matter, study finds Writing in the Proceedings of the National Academy of Sciences journal, the Australian researchers said their findings suggest that the choices of women may have caused men to develop larger penises during human evolution. Women's inclination towards men with a larger manhood could be down to enjoying greater pleasure during previous sexual liaisons, or may be an "aesthetic preference," they wrote. The study found that being tall and particularly having broad shoulders relative to the hips also played a significant role in men's attractiveness. Although the factors are tied to one another the shoulder-to-hip ratio explained about 80 per cent of variability in men's attractiveness in the study, while height accounted for 6 per cent and penis size for 5 per cent. The researchers, said their results "directly contradict claims that penis size is unimportant to most females." Dr Brian Mautz of the Australian National University, Canberra, said: "We found flaccid penis size had a significant influence on male attractiveness. Males with a larger penis were rated as being relatively more attractive. Our results show female mate choice could have played a role in the evolution of the relatively large human male penis.