Most adult men have taken a sexual education class and know that condoms prevent the transmission of sexually transmitted diseases and infections, according to the Centers for Disease Control and Prevention While this is common knowledge, a new study shows that men are more willing to skip wearing a condom if they think their partner is attractive. Researchers at the University of Southampton and the University of Bristol determined this by studying 51 heterosexual men.They showed the men photos of 20 women and asked them to rank their attractiveness from 0 to 100. Then, researchers asked the men to "estimate the likelihood" of the woman having a sexually transmitted disease and rate how likely they were to sleep with the woman and use protection while doing so.The results are surprising. The closer a man ranked the woman to 100, the more likely he was to sleep with her without using condoms. Lead researcher Anastasia Eleftheriou told The Washington Post that the research held true "even though they might believe that those women are more likely" to have sexually transmitted diseases.