A very common problem I hear is 'I get to river spots and "I know I should fold" or "I know he has got it", but they claim they still call'.

First, this could be the pure fact/psychology that we most remember the times we get burnt (useful as an evolutionary trait). And perhaps 1/x times hero call works and therefore a call could be justified to this polarised bet. But I am looking to dismiss that, as I always discuss that first.

When trying to look for a solution, I typically just try to get friends/students to start taking these spots as a mathematical situation, for which at the given price (plus vs given population/scenario), they need to call x% theoretically, unless something clearly tells you otherwise (in which case we try to not drastically over-react if we are prone to errors in one direction), and then we live with the results.

But is there something else more from the mental side I need to consider and I am missing? Why do people do this and how can they best stop?

I am something of a robot when I play so I probably miss the psychological elements of this a little.