General Mental Abilityaka (GMA)

aka (g factor)aka (g)

John Breidert&

James Hellrung

GMA Haiku

General Mental TestsOne Concept With Many Parts

Test the “g factor”

OverviewIntroduction into GMA and Supporting

TheoriesGMA on the job and in tests

Introduction into GMA and Supporting TheoriesIntroduction to General Mental AbilitySpearman’s Two-factor Theory of IntelligenceVernon’s Hierarchical Theory of IntelligenceCarroll’s Three-Stratum Factor Analytic

Theory of Cognitive Abilities

Introduction to General Mental Ability

General Mental Ability is the sum of many parts of intelligence

Building Example

Spearman’s Two-factor Theory of Intelligence

Spearman (1863- 1945) Proposed the theory in 1927

General Factor (g) in addition to one or more specific factors accounted for people’s performance on intelligence tests

Spearman saw the g factor as a mental energy that was expended on different mental tasks

Spearman saw the g factor as more of the inventive aspect of mental ability

Spearman’s Two-factor Theory of Intelligence

Vernon’s Hierarchical Theory of Intelligence

Philip E. Vernon (1950)Hierarchical theory of intelligenceg at highest level, must consider it in order to

understand or measure intelligenceAt next level are the major group factors:

Verbal-EducationalSpatial-Mechanical

Vernon’s Hierarchical Theory of IntelligenceNext level is minor group factors:Lowest level contains specialized factors that

are unique to specific testsTherefore, the lower on the hierarchy, the

most specific the behaviorVernon’s theory is supported by numerous

studies finding positive intercorrelations among different tests

Vernon’s Hierarchical Theory of Intelligence

Carroll’s Three-Stratum Factor Analytic Theory of Cognitive AbilitiesJohn B. Carroll (1993) proposed a three

stratum factor analytic theory of cognitive abilities

There are many distinct differences in cognitive ability

Carroll’s Three-Stratum Factor Analytic Theory of Cognitive AbilitiesNarrow (stratum 1)

65 narrow abilitiesLevel factorsSpeed factorsRate factors

Broad (stratum 2) 8 broad factors

General (stratum 3)Consists of only g

Carroll’s Three-Stratum Factor Analytic Theory of Cognitive Abilities

GMA on the Job and in TestsGMA and Occupational LevelGMA and Job PerformanceGMA and Training PerformanceOther Traits and Variables Affecting Job

PerformanceGroup Differences for GMAGeneral Reactions to GMANew Methods of Testing GMA

GMA and Occupational LevelCross-sectional & Longitudinal Studies relate

GMA to occupational levelCross-sectional Studies – mean GMA increases

with occupational levelLongitudinal Studies – GMA measured earlier in

life predicts later occupational level. Job mobility predicted by congruence between

peoples’ GMA scores and complexity of their job Childhood GMA predicts adult occupation level (r

= .51) and income (r = .53)GMA predicts attained job level, but not which

occupation within that level

GMA and Job PerformanceGMA used for predicting Job Performance

since WWISituational Specificity theory says GMA

predicts job performance sporadicallyValidity coefficients varied across studiesSome statistically significant, some not

Truth – variability in validity findings due to statistical and measurement artifacts.After correcting for effects of artifacts, there

was little variability in validity, and GMA measures were predictive of job performance for all jobs.

GMA and Job PerformanceValidity ranges

.58 for most complex jobs.23 for least complex jobs

Validity for job performance shown in many studies:Clerical jobs - .52 (Pearlman, Schmidt, & Hunter, 1980)Law Enforcement - .38 ( Hirsh, Northrup, & Schmidt

(1986)Military “Core Technical Proficiency” - .63 (McHenry et

al., 1990)Military “General Soldiering Proficiency” - .65 (McHenry

et al., 1990)Air Force jobs – mean of .45 (Ree, Earles & Teachout,

1994)

GMA and Training PerformanceValidity for training performance also:

Meta-analysis of 90 studies - > .50 (Hunter & Hunter, 1984)

Military meta-analysis of over 82,000 trainees - > .63 (Hunter, 1986)

Air Force meta-analysis of over 77,958 trainees - > .60 (Ree & Earles, 1991)

Clerical workers – mean of .71 (Pearlman et al., 1980)Law enforcement – mean value of .76 (Hirsh et al., 1986)

Across meta analyses, unweighted average validity:.55 for job performance.63 for training performance

Other Traits and Variables Affecting Job PerformanceSpecific Aptitudes

Cognitive abilities narrower than GMARegression equations optimize prediction of job and training

performanceDisconfirmed - Causal analysis modeling failed to fit the data,

but a hierarchical model fit well (Hunter, 1983b)Use of specific aptitudes may reduce group differences

Job ExperienceMore job experience, not GMA should predict job performanceAs experience increases, predictive validity of GMA does not

decrease. Actually goes from .36 for 0-6 years to .44 for 6-12 years, up to .59

for more than 12 years. If anything, as experience increases, so does validity of GMA

Other Traits and Variables Affecting Job PerformancePersonality Traits

Predicted occupational level and income (Judge et al., 1999) Conscientiousness : .49 and .41 Openness to experience: .32 and .26 Neuroticism: -.26 and -.34 GMA: .51 and .53

When placed career success in regression equation: Multiple r = .63 Neuroticism: β = -.05 Openness: β = -.03 Conscientiousness: β = .27 GMA: β = .43

When only Conscientiousness and GMA in equation: Multiple r = .63

Conscientiousness is only personality trait contributing to career success

Group Differences for GMASpecific aptitudes have smaller group differences

May be due to unreliability and range restrictionHowever GMA tests are more reliable than other predictorsGMA produces racial differences

3-5 times more difference than produced by interviews, biodata, and work sample tests. Could be due to measurement error in the above

Four-fifths ruleInfers adverse impact when selection rate for the low-scoring

group < 4/5 the selection rate for the high-scoring groupBecause job complexity increases the likelihood of adverse impact,

Viswesvaran & Ones (2002) suggest a sliding adverse impact rule (e.g., .50 for complex jobs and .80 for simple ones)

GMA is a best predictor of job performance, but also predictor with most adverse impact

General Reactions to GMAEven students who are not aware of group differences

have negative reactionsIn homogenous societies, there are also negative

reactions to GMA (Viswesvaran & Ones, 2002)Past abuses of testing for GMA still haunt usResearch on applicant reactions to GMA needs to

continue, but still at its infancyLaypeople maybe convince that cognitive ability is not

important in determining intelligent behavior.Although research suggests validity of GMA increases

with increased job complexity, organizations are less likely to use GMA for high-level jobs than lower-level jobs. (Face validity?)

New Methods of Testing GMALow cost of paper & pencil

Killed demand for other testing mediaTo reduce group differences

One strategy is to change test medium Computerized and video-based assessments

Must be careful not to change construct being measured Format changes may induce differences in GMA and

individual differences in responding to the new medium

New Methods of Testing GMAIn the future:

May see tools based on physiological, biological, and genetic markers identified for GMA Whether they are accepted depends on societal

views on privacy rights versus organizational needs

Bottom line – If the use of different mediums reduces adverse impact without reducing validity for a criterion, then the new method is preferred

Questions?