The study of the human brain and its behaviours.
There is a level of metacognition involved in this. And while philosophy is mostly theoretical, this one uses things like statistics to try to objectively learn the human nature of the average human mind.
I am actually so aware of the state of mind, that the brain experiences what psychological feelings it has. But other than detachment, it's very hard to rewire it without adverse side effects.
See:
Bias
Fallacy
Motivation