Prepare for the speculation, which is something that I sometimes do, sorry, you have the sources linked so you can draw your own conclusions.

High levels of dopamine seem to be associated with contentment, so anxiety is probably related with low levels of dopamine, with is related with high IQ and memory. Once again intelligence and happiness seem to be contrary.

The second part is more tricky. It is stated that self-confidence in intelligence may be unrelated with real IQ but is related with grades. What is the cause and the consequence between the high grades and self-confidence? May that mean that IQ tests are in fact not measuring intelligence? It is in fact tricky, but now take the first part again.

Self-confidence seems related with high levels of dopamine, which is related with not-so-good IQ, but good grades. So if you are happy with your IQ chances are that it is not so high.

Well, that made sense.

However the brain is a complex system, a small change may have