Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 exptools 1/6/84; site iham1.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!ihnp4!iham1!gjphw From: gjphw@iham1.UUCP Newsgroups: net.misc Subject: Re: Re: IQ Statistics, Anyone? - (nf) Message-ID: <220@iham1.UUCP> Date: Thu, 27-Sep-84 15:19:47 EDT Article-I.D.: iham1.220 Posted: Thu Sep 27 15:19:47 1984 Date-Received: Fri, 28-Sep-84 07:08:34 EDT References: <217@iham1.UUCP>, <10600172@uiucdcs.UUCP> <1231@ihuxq.UUCP> Organization: AT&T Bell Labs, Naperville, IL Lines: 39 This is just a brief contribution to the topic of the distribution of IQs based upon an article disussing this in the present Encyclopaedia Britannica (Brintannica III). While the Stanford-Binet IQ test has been standardized to yield a normal or bell-shaped distribution with mean of 100 and standard deviation of 15 or 16, the normal distribution fails beyond the 95% level. For IQs above 125, about twice as many people exist in the general population as would be predicted from a normal distribution. Below about 85, there are three times as many people as indicated from a normal distribution. The high IQ population is explained as due to the high correlation that exists between marriage partners and their offspring. Statistically, high IQ people marry other high IQ people and raise high IQ children. A normal distribution assumes that all measured quantities are uncorrelated, so having correlated marriage partners violates this assumption and reveals itself where the population become small (IQs above 125). The low IQ population is described as due to a variety of causes. Any injury to the brain, due to illness, accident, or prenatal development, almost always lowers the measurable IQ. Since all kinds of problems that can happen to people virtually never acts to raise IQs, the ills that may befall anyone provide the source to increase the low IQ population. IQs are supposed to be reasonably well correlated (better than 0.5) with students' grade point averages through elementary and secondary schools (for IQs between approximately 90 and 125). Both IQs and GPAs are poorly correlated with success in adult life. Excuse me while I return to playing with my mental blocks... -- Patrick Wyant AT&T Bell Laboratories (Naperville, IL) *!iham1!gjphw