People have beliefs , then use reason as a tool to defend their beliefs and attack opposing beliefs.
Yet in the 1970's, feminist anthropologists discovered some aboriginal cultures in which the sex roles appeared to be reversed. Another example from nuclear physics is the famous case of the Omega Minus particle. Theory had predicted its existence. This led to years of effort and millions of dollars in research before the particle was finally discovered and photographed. That is why the latest two-year study of America's sex life comes as such a surprise.