Using IQ as a predictor

• What should IQ predict? (And does it?)

  
• A problem with using IQ as a predictor: Intelligence is malleable.

  Ceci (1990)

  • Meta-analysis
  • Children who attend school regularly score higher on IQ tests (a rise of 2.7 points).
  • Delays starting school cause intelligence to drop (by 5 IQ points per year missed).

  Wahlsten (1997)

  • An infant moved from a family with low SES to a family with high SES, will improve the infants IQ score.
• A problem with using IQ as a predictor: Understanding the mechanism.

  Whalley and Deary (2001)

  • Traced 80% of people born in 1921 who took part in the Scottish Mental Survey of 1932 in Aberdeen city (n= 2,230 from 2,792).
  • They used medical and public databases to find whether people were still alive at age 76 in 1997, 65 years after the IQ test.
  • People with a standard-deviation (15-point) disadvantage in IQ score relative to others at age 11 were only 79% as likely to live to age 76.
• IQ and mortality: Deary and Der (2005):

  Deary and Der (2005): Hypotheses

  • (A) High IQ associated with more optimal health behaviours
  • (B) High IQ is predictive of educational qualifications and social classes that confer entry to safer environments.
  • (C) IQ might be related to mortality because mental ability tests assess some aspect of bodily integrity.
• IQ and mortality: Deary and Der (2005)

  What did they do and find?

  • Investigated this in a sample 898 people from Scotland. • Intelligence measured at 56, looked at who was alive 14 years later.

  Found that:

  • Association between intelligence and mortality was only partially driven by smoking, education and social class (A & B)
  • Association between intelligence and mortality not significant when taking reaction time into account (C).
• A problem with using IQ as a predictor: Do they predict?

  Klemp and McClelland (1986):

  • Scores on standard ability tests ‘tend to be uncorrelated’ with actual proficiency in managerial jobs and with performance on simulated business problems, used as part of an assessment programme.
• Problems in IQ tests are too well defined

  In real life, problems are rarely so clear-cut

  • Before figuring out a solution, one must first figure out the problem -> only then can one know what kind of information to seek out (it is not given) in order to solve it à and then choose a solution, usually from among several possible solutions.”