According to a study from the National Bureau of Economic Research, about 20 percent of the population is attracted to their own gender. That’s nearly double the usual estimates of about 10 percent. The authors explain that their methodology might have something to do with it: Participants were randomly assigned to either a “best practices method” that was computer-based and provides privacy and anonymity, or to a “veiled elicitation method” that further conceals individual responses. Answers in the veiled method preclude inference about any particular individual, but can be used to accurately estimate statistics about the population. Comparing the two...