In 1948, it was impossible to gather a valid sample of American male sexual practices (“Hello, I’d like to ask you a few questions about your lover”). It would be difficult today. And in 1948, just as now, it was difficult to gather ethical data about the sexual responses of baby boys. Weapon of Mass Distraction provides more information about exactly what Alfred Kinsey did instead.
Why did anybody believe him then and buy his books? Why does anybody believe him now and pay to watch films about him? Because we want to believe him. We want to believe that scientists can learn anything and everything, even though Heisenberg and other quantum physicists proved otherwise. We want to believe that fornication and adultery are normal and harmless, even though centuries of human history have proven otherwise. It doesn’t matter. Because an expert told us so, and the experts are like gods.