galton

What you're describing is 'regression to the mean.' Francis Galton noticed this effect when he was studying the traits of various genetically influenced traits.

Remember one of the origins of research into intelligence: Galton researching English geniuses and noting they were often related.

For those not in the know, Galton invented the simplest way of understanding normal distribution.

This is fascinating to me; as is the Galton reference ~gwillen points out, which suggests about 3% of people don't form mental images at all.

Wow, the Galton paper is amazing, thank you.

This is the kind of mental test that Galton and James McKeen Cattell did a century ago, and those tests were found to have no valid correlation with intelligence.

I wonder, however, whether the surname analysis took into account the effects of the changes in surname frequency over time -- as I recall, it was Galton who investigated statistically how the surname distributions change with time, and the point is that the number of unique surnames goes down over time, because each child usually has only one of their parents' surnames.

This was Francis Galton's theory of intelligence more than a century ago, but repeated studies have shown that sensory discrimination is very poorly correlated with anything that can properly be called "intelligence" among adult test-takers.

The earliest mental tester, Galton, recognized that he had no "foot rule." Early on, he was frustrated by the lack of an "external standard of measurement" for what he was investigating, and resolved to report his results as a rank-ordering of subjects, without a "foot-rule" (Galton 1880).

An exceedingly simple model, the Galton-Watson process, was introduced in 1875 and exhibits the behaviour of the 'reproduction number'.

Galton gave people some very detailed surveys, and found that some people did have mental imagery and others didn't.

People forget that Galton's original example was with a group of people with good domain knowledge.