Why Do We Do This? (of course, not all of us do)

[Lat-Literal]

... actually it is about putting forward theories, and then seeking to find evidence to contradict them.

https://en.wikipedia.org/wiki/Falsifiability

.

Yes - and the problem with psychology is that it tends to be applied biblically and subjected not to contradictions as such but simply different opinions. Like others, I attempted to answer the question in the OP but I realise now this went against my general grain. That is, I see in the history of psychology weighty tomes by the supposedly all-knowing. Inevitably there were biases given their individual flaws. The other side of the coin is mainly sampling with "experts" having an authorised overview. What there isn't other than in the soft areas of counselling is scope for individuals among the sampled to form the authoritative overview. In this instance, that would involve Mr Oven answering his own question and then being given sufficient credibility even among those of us who think we know better not only to be right but to be right with a wide applicability, ie his rightness would apply to similar others.

[greenilex]

I know at least one eminent psychologist who spends his time with brain imaging machinery and would be amazed if anyone suggested his methods were not rigorously scientific.

[Serial_Apologist]

I know at least one eminent psychologist who spends his time with brain imaging machinery and would be amazed if anyone suggested his methods were not rigorously scientific.

Psychologist? Or neurologist?

[greenilex]

Well, his professorship is in psychology. He is not a medic in any sense.