I don't think we - people used to STEM - appreciate how difficult behavioral psychology is. In STEM, we are used to isolating experiments down, so there are as few variables as possible. And we are used to well-designed experiments being reproducible if everyone does what they are supposed to do right.

In the study of human behavior there are always countless uncontrollable variables, every human is a bit different and it is very difficult to discover something that would apply generally. Also, pretty much all of the research is done on western population of European descent.

This is why I take all behavioral claims with a large grain of salt, but I still have respect for the researchers doing their best in the field.