Marshmallow test

It is interesting but I am really shocked to learn that all of these psychologists didn't realize that tests like these are inherently flawed because they can't control the variables and all individuals are different even if you take a group that grew up in the same culture. And it's not even so much that the tests are flawed, it's that they have attempted to make hard science, objective conclusions for all children from tests that don't have a control group and are at best subjective tests for each child. I mean, you can probably come up with some general concepts from tests that this but they should always have a big disclaimer that they are only useful as a guide and don't apply to all children everywhere.

I mean, it's always been clear to me that psychology, particularly, the research end of it is not hard science because medical ethics does not allow for a true control group and limits the types of testing that we will allow.