Date: Wed, 6 Dec 1995 23:58:43 -0800 From: Rima & Kim McKinzey Subject: Vocabulary & IQ As the psychologist husband in question, I've been asked to clarify. First, I qualify as a well-educated, up-to-date, licensed clinical psychologist (Ph.D.). I'm a member of APA, & have been an examiner for CA. I am qualified to document a person's IQ (whether for SSI, school, court, or Mensa), and keep informed on available indices of IQ. I don't think there's a better intro to the topic than Matarrazzo. I defer to him as an authority. IQ isn't a difficult concept; the various definitions are usually summarized as "figuring things out," altho I prefer "adapting to novel tasks." Once the concept has been operationalized (i.e., a criterion has been agreed upon), standarized measures can be devised to fulfill the need for the measure. Historically, that need came when schools sought a way of giving special aid to the lower 2% of the child population, and again when this nation's military sought a way of making the most of the hordes of men suddenly being processed at the entry of WWI. As psychologists kept at it, our tests got more sophisticated (the WAIS-III is in development!). Spearman's G (the notion of a general, overarching factor) and related special intellectual abilities (see the description of Gardner's ideas) seemed pretty reasonable as an approach. My predecessors discovered that once a G score (such as the WAIS-R FSIQ) was formulated, Vocabulary (followed by Similarities) correlated the highest with the overall score in both adults and children. Hence, the PPVT, Shipley ILS, and shorter forms of the WAIS usually include some well-normed measure of vocabulary. Hence, Rima's carefully chosen "vocabulary is amongst our best indicators." Now: what to do about people who are not from the normative population? We have a host of "culture-free" tests; I like the Raven Progressive Matrices best. Those tests use language-free problems to get at the IQ, and do acceptably at getting at IQ potential. The referral question must be considered. If the question is: this child is having trouble in school. Should we give special attention to her? The answer is, yes, why do you need an IQ? If the question is: will this applicant do well in a computer customer service position? I'll use a highly verbal test, or even verbal ability during an interview. If the question is : should we kill this defendant, or let him live? The answer is: here are the results of both verbal and non-verbal measures, plus many others. >it is historically characteristic of reductionist thinking in psychology to equate vocabulary with intelligence. Has anyone ever done this? Or are we talking about useful predictors? > I hear of psychologists using the vocabulary to assess the level of cognitive development as well as intelligence. >My apologies to your husband the psychologist Accepted. >While this might be a relatively effective device for a homogeneous population (and I doubt that it is really effective there) Science (as opposed to opinion) disagrees. > in the midst of diversity, it is almost as poopy as dialect prejudice. The presence of some folks in the population that are not represented in the normative sample of the given test does not invalidate the test, it only limits the interpretation. >My father ...told me about Leonard Bloomfield's success in raising his childrens' IQs in a very short time by simply drilling them in vocabulary. Surely this group understands the fallacy of "teaching the test"? >I'd be surprised if there were any significant differences in vocabulary size by discipline. Has any research been done on this? Oddly enough, yes. R.K.McKinzey, Ph.D.