Certain clinical studies have used the same technology used to test convicted pedophiles for arousal when shown pictures of nude children in order to study homophobes. The device measures change in penis width. Apparently, people with proclaimed anti-homosexual beliefs showed signs of arousal when presented with video footage of homosexual activities. Some, however, have ascribed this not to latent homosexuality in the subjects but to nervousness on the part of the subjects when presented with the objects of their animosity. Nervousness tends to cause increased bloodflow to extremities, and can simulate sexual arousal. Incidentally, groups claiming to be able to cure homosexuality such as Exodus International refuse to use similar methods to test the effectiveness of their treatments on claimed ex-homosexuals.