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Intelligence, IQ, and Crime. History of mental testing and IQ The relationship between IQ and Crime Issues of Spuriousness Direct, or Indirect Effect Criticisms of the Bell Curve. Alfred Binet. French scientist who began in the field of “craniometry”

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intelligence iq and crime
Intelligence, IQ, and Crime
  • History of mental testing and IQ
  • The relationship between IQ and Crime
  • Issues of Spuriousness
  • Direct, or Indirect Effect
  • Criticisms of the Bell Curve
alfred binet
Alfred Binet
  • French scientist who began in the field of “craniometry”
    • Began to doubt the validity of this method
    • Around 1900, he started “psychological” testing

(commissioned by government)

    • Devised several “mental tasks” (counting coins, spatial reasoning)
binet s admonishments
Binet’s Admonishments

1.Scores are a practical device

  • They do not buttress any theory of “intelligence”

2.Scores are a “rough empirical guide” for identifying retarded children

  • They should not be used to rank normal children

3.Children identified as retarded should be helped

  • Low scores should not mark children as “innately incapable”
the creation of iq
The Creation of “IQ”
  • Binet: eventually assigned an “mental age” to each task (normal child x years of age should complete)
    • Subtract the physical age from the mental age to see how big the gap was (identify those in need)
  • Later, others argued that the mental age should be divided by the physical age
    • “Intelligence Quotient” was born
the american bastardization
The American “bastardization”
  • Binet’s methods adopted by scientists in U.S.
    • They managed to break all of the “rules”
  • H.H. Goddard
    • coined the term “moron,” set at a mental age of 12 for an adult
    • avid in the eugenics movement
  • Lewis Terman
    • Created the “Stanford-Binet” IQ exam
    • Goal = “rational society” where people could be assigned jobs based on intelligence
iq tests today
IQ tests today
  • No longer “mental age/physical age”
  • All correlate with the Stanford Binet or other early versions
  • Calibrated to produce a mean of 100
  • The “Flynn effect”
  • Still multiple tasks covering different cognitive areas

Seven J. Gould

  • Two biggest mistakes regarding IQ scores
    • 1. Reification
    • 2. Hereditarian fallacy
iq and crime
IQ and Crime
  • Early positivists (Goddard…) found large differences between criminals and non-criminals
    • As testing improved, this difference shrunk
    • Sutherland (1940s): it will disappear
  • Currently: 8-10 point gap
  • Why this difference???
possible spuriousness
Possible Spuriousness
  • Race, Class, SES, Culture?
    • Controlling for these effects, the relationship remains
  • Detection Hypothesis?
    • Detected vs. Undetected offenders = no difference
  • Impulsivity?
    • Ruled out through statistical control
if relationship is non spurious
If relationship is non-spurious
  • The “Direct Effect Model”
    • (The Bell Curve)
    • Low IQ Crime
  • Indirect Effects
    • Low IQ school trouble Delinquency

labeling process

  • Interactive:
    • Low IQ is proxy for neuropsychological damage
    • (N.P. damage x Parenting) Delinquency
criticisms of the bell curve
Criticisms of the Bell Curve
  • Only 3 variables in model (not enough control)
    • Could control for school performance, other factors
  • IQ explains only 3% of the variation in crime
    • The correlation is about .-06
    • Is this important enough to justify their policy implication??
  • Ranked with other “predictors,” IQ is near the bottom of the list