Gifted Issues Discussion homepage Forums General Discussion Who Noticed First?

Regression to the mean deals with random error in the measurement of something. It tells us nothing about that something.

It only applies to measurement, not the particular cause and effect of a given thing you are studying. The cause and effect have to be established before we can measure and then say what any mean is.

http://en.wikipedia.org/wiki/Regression_toward_the_mean

In talking about IQ, we can say someone's IQ is Z and on any given day they will test within X points of it. As they take the test over time the scores will regress to the mean of Z.

As for kids. It has already been shown that intelligence is both heritable and is affected by environment. There is also the Flynn Effect. Thus one would expect that children of highly intelligent and committed parents would also be intelligent, probably more so.

Based on the above, "families" with parents of similar traits do not "slide back" to "average" which is the underlying assumption of misusing "regression to the mean" to describe a particular person's performance.

Another way it could be misused is the "all kids catch up" by third grade. Intelligence is not something that goes away as kids get older all things being equal. IQ remains as a fundamental part of their individuality.

Regression in genetics is different than regression to the mean in statistics. The genetic regression depends on the trait under study. A tall family will have tall kids. They will not suddenly become Hobbits. And regression in genetics is still a way to "account" for things that cannot be measured and hence are "random" in appearance.

All I know is that low IQ runs in families, which is how you can represent multiple generations for the same disability of mental retardation (70 or below, for my purposes).

More precisely, we could say that "g" the theoretical and controversial idea of the general intelligence behind IQ does not normally change. There are several reasons why IQ--attempts to measure g--might change, especially from younger ages to older ages. For example, my own measured IQ changed 24 points between second grade and sixth grade, but that does not mean there was an abrupt change in my cognitive ability.

And by the way, my own set of siblings includes people with IQs in the genius, mentally retarded, and high average ranges, as well as some whose IQs have never been measured.

Mine has teen pregnancies. My grandmother got to become a great-great-grandmother before she died.

Since "crystallized intelligence" relies on acquired information, such as vocabulary, there is a greater environmental impact.