There are so many different types of cognitive errors that they could fill a bookâjust not this one! Instead, I want to draw your attention to a few poorly understood mental processes and the ways they work against your best interest. The average investor knows little about some of the fascinating cognitive deficits, including the Dunning-Kruger effect, epistemic trespass, and cognitive dissonance. We will also delve into the relatively young field of neuroeconomics.