History and Impact of IQ Testing

Introduction to IQ Testing

• Developed by Alfred Binet and Theodore Simon in 1905.
• Originally designed to help children struggling in school in France.
• Basis for modern IQ tests.

Concept of General Intelligence

• Cognitive abilities like verbal reasoning and memory were thought to reflect a general intelligence (G-factor).
• Binet and Simon's battery of tests measured various abilities to produce a single score.
• IQ score: Calculated by dividing someone's score by their age and multiplying by 100.
• Average IQ score is 100, with 68% of people scoring within 15 points of 100.

Controversies and Misuses of IQ Testing

• No single agreed-upon definition of general intelligence.
• Tests used in ways not intended by the creators, often promoting biased ideologies.

Early Misuse in the United States

• Large-scale IQ testing in WWI for military recruitment and officer training.
• Influenced by eugenics, leading to erroneous claims about racial intelligence.
• Many recruits were immigrants with little education or English exposure, skewing results.

Eugenics and Policy Influence

• Eugenics: Belief in controlling genetic traits through selective breeding.
• Virginia's policy in 1924 for forced sterilization based on IQ.
• Nazi Germany's use of IQ to justify murders.
• Discriminatory uses challenged post-Holocaust and Civil Rights Movement.

Scientific Developments and Criticisms

• Flynn Effect: New generations scored higher on old tests, suggesting environmental factors like education and nutrition impact IQ.
• Mid-20th century attempts to use IQ tests for psychiatric diagnostics, later found invalid.

Current Uses and Issues

• IQ tests not used for psychiatric conditions today.
• Subtest scores still sometimes used improperly for diagnosing learning disabilities.
• Used to identify intellectual disabilities and support educational/job training decisions.

Conclusion

• IQ tests have been used to justify harmful policies and ideologies.
• They measure reasoning and problem-solving skills but not a person’s potential.
• Growing consensus against categorizing individuals by a single numerical score.

Further Exploration

• Discussion on standardized testing and its implications.
• Examination of the Rorschach test.