General Mental Ability

1. General Mental Ability Alicia Turner Tricia Slack

2. Overview • What is General Mental Ability? • Spearman’s Two-Factor Theory • GMA Tests • GMA Themes in the IO Field • GMA and Job Factors • Traits and Variables

3. What is General Mental Ability? • The ability used in calculating, reasoning, perceiving relationships and analogies, learning quickly, storing and retrieving information, using language fluently, classifying, generalizing, and adjusting to new situations • Alfred Binet defined intelligence as the totality of mental processes involved in adapting to the environment

4. General Factor (g) • Early investigations into intelligence assumed that there was one underlying general factor • Spearman researched the existence of a general factor of mental ability (the g factor) that enters into all cognitive tasks • g itself is not an ability, but some property of the brain that causes all forms of mental abilities to be positively correlated

5. Two-Factor Theory • Spearman at first argued that the true scores on each mental test reflected only two factors – the g factor common to all tests and also a factor that is specific to each particular test g s1 s2 s3 s4

6. G Factor • The underlying physiological causes of individual differences in g are still largely undetermined • We now know that g is more genetically heritable than are any other ability factors measured by mental tests • Also, g has more anatomical and physiological brain correlates than other psychometric factors.

7. GMA Tests • Tests of GMA have been widely used for nearly a century for personnel selection • Abilities commonly measured in GMA tests include reading, spelling, vocabulary, math, reasoning and classifying • Items are usually presented in multiple-choice format. • Studies consistently yield validity coefficients of .5 to .7

8. Wonderlic Personnel Test • The most commonly used measure of General Mental Ability • Consists of 50 free response items • 10 minute time limit • Has numerous parallel forms available • Extensive norm data is available

9. Criticisms of GMA Tests • Caucasians consistently achieve higher scores on GMA tests than do African-Americans and Latin-Americans • Resulting in disparate treatment • Often lack face validity

10. 8 Current GMA Themes in the IO Field • Predictive value of GMA for real-life outcomes and work behaviors • How high should a substantial correlation be? Are corrected validities reflective of the true value of the test? Is intelligent behavior a result of more that just what intelligence tests measure? • Predictive value of GMA versus specific abilities • Empirical findings that relate to the lack of incremental validity of specific abilities over GMA have been limited to a handful of criteria • The consequences of the criterion problem for GMA validities • Disagreement about whether training performance should be used as a criterion. Criterion should measure organizational effectiveness, not just individual performance

11. 8 Current GMA Themes in the IO Field • Is utility evidence for GMA convincing? • Findings differ in the utility of GMA with correlations as low as .30 due to which interests are included in the model • Are the negative reactions to GMA tests a result of group differences? • People have negative reactions to GMA tests without group differences, Debate between valid predictor and adverse impact suggest exploring the possibility of a sliding adverse impact rule • Is theoretical knowledge of GMA adequate?

12. 8 Current GMA Themes in the IO Field • Is there promise in new methods of testing for GMA? • May reduce adverse impact • What is the current status of non-GMA predictors as substitutes or supplements to GMA? • Some researchers advocate using personality, job knowledge, and work sample tests but issues of equal validity vs. equal value

13. GMA and Job Factors • Scores in measures of GMA correlate highly with several job factors. • Occupational level • Job Performance • Training Performance

14. GMA and Occupational Level • Both Cross-sectional & Longitudinal Studies relate GMA to occupational level • Mean GMA increases with occupational level • As a result, individuals with low GMA scores find it hard to enter higher level occupations • GMA measured earlier in life predicts later occupational level (r = .51) and income (r = .53) • Measures of job complexity are highly correlated with measures of GMA • If GMA is higher than the complexity level of their current job, they are likely to move in to a more complex job • GMA predicts ultimate job level, but not occupation

15. GMA and Job/Training Performance • Situational Specificity theory says GMA predicts job performance sporadically • However, it is highly situational • Some studies have found significant results, while others have not • Due to statistical and measurement artifacts • When corrected for, r = .50 • Additional studies found validity ranges: • .58 for most complex jobs • .23 for least complex jobs

16. Other Traits/Variables that Affect Job Performance • Specific Aptitudes • Refer to cognitive abilities that are narrower than GMA (s factor) • Differentially weighting specific aptitude tests do not increase validity over using GMA alone

17. GMA Causal Model

18. Other Traits and Variables Affecting Job Performance • Job Experience • Job experience predicts performance ratings (r = .49), but only for new hires (0-3 years on job) • Predictive value decreases as years increase (r = .15) for ≥ 12 years on the job • Predictive value of GMA remains constant as years on the job increase

19. Other Traits and Variables Affecting Job Performance • Personality Traits • Have less predictive value than GMA for both job performance and occupational level • Conscientiousness is the only personality trait that has been found to function like GMA in consistently predicting job performance

20. Questions?