Anchoring effect is a very simple one and easy to replicate. But in general the psychology knowledge is a lot less certain than that of natural sciences, preci

Anchoring effect is a very simple one and easy to replicate. But in general the psychology knowledge is a lot less certain than that of natural sciences, precisely because the experiments are very difficult to conduct and the results often turn out to be irreproducible. Also, people are diverse and behave diversly and it is impossible to get a sample that represents humanity for your experiment.