Scientists who study sexual desire have long been wary of over-relying on self-report data because people don’t always tell the truth on surveys. Some people answer questions about what turns them on and what their sex lives are like in whatever way makes them look best. For example, someone might underreport their sexual desires and experiences in order to appear wholesome, or perhaps because they don't want to own up to something. To get around this issue, many sex scientists utilize devices that can measure genital arousal under the assumption that “genitals don’t lie.” Among researchers who subscribe to this belief, they have a tendency to let genital data trump self-report data whenever they seem to be saying different things.