The most trivial brain training exercises routinely show major increases in IQ scores. Those who favor a static hypothesis (and they seem to be the majority) like to simply assume these are fake gains. But without ground truth, there's no way to know. You'd also be surprised how few studies there are that have people directly practice IQ test taking.
The static hypothesis seems to rely on common sense rather than hard evidence. It's rare for somebody who seems dull to become a genius all of a sudden. And when it does happen it's easy to assume they seemed dull rather than actually were.
There is no disconnect between intelligence being simple yet hard to improve. Losing weight is very simple. But it's hard. Obesity is only slightly less heritable than IQ (both highly heritable), yet we know for a fact it's 100% controllable by the individual (unless one is strongly against the notion of free will).
The static hypothesis seems to rely on common sense rather than hard evidence. It's rare for somebody who seems dull to become a genius all of a sudden. And when it does happen it's easy to assume they seemed dull rather than actually were.
There is no disconnect between intelligence being simple yet hard to improve. Losing weight is very simple. But it's hard. Obesity is only slightly less heritable than IQ (both highly heritable), yet we know for a fact it's 100% controllable by the individual (unless one is strongly against the notion of free will).