Biology was far luckier in general, in that biology is a much better subject for scientific inquiry than psychology. Good science has to work very hard to keep

Biology was far luckier in general, in that biology is a much better subject for scientific inquiry than psychology. Good science has to work very hard to keep subjectivity and bias at bay; they are constantly and insidiously trying to creep in, and they are poison. Psychologists have the unlucky job of trying to scientifically study subjectivity and bias itself. I don't think it's really possible to make psychology a rigorous science; the subject may simply be out of reach.