[hollander]

It's generally acknowledged that IQ measured by well known IQ tests like the WAIS are fairly consistent over time. You may score a few points lower or higher, but it won't change much. Training can help a bit, but only so much. Health issues, mental problems, stress, tiredness, drugs or alcohol can all influence your score, mostly in a negative way. So I suppose that influences like these are filtered out of this research. They are interesting to research, to see what their influence is, but to study the consistency in test results over time, they should be left out.

[astrange]

> It's generally acknowledged that IQ measured by well known IQ tests like the WAIS are fairly consistent over time.

This is partially because they're designed to behave that way. There is not a direct causation between your score on a test and your quality of life.

Also, how many people are actually taking IQ tests multiple times in their life? Who even takes them once unless they're being studied for a mental health issue?

> Health issues, mental problems, stress, tiredness, drugs or alcohol can all influence your score, mostly in a negative way.

… and this is a counterpoint to the one above, because removing negative contributions is the same thing as improving your test score.

[bloqs]

Plenty of people, particularly people employed by large institutional bodies like the the worlds mililitaries, many participating in long term studies, people being assessed for schools and colleges for learning difficulties, people joining a variety of institutions like mensa or applying to a range of jobs

[astrange]

I think only "participating in long term studies" counts here, the rest don't actually get results that can be compared over time. And if you're taking the rest because you have learning difficulties, why would the results apply to humanity in general?