core - individual differences

• Trying to define intelligence has proved problematic so researchers have tended to focus instead on testing intelligence, whatever intelligence may be!
• Nature and nurture


  Is intelligence innate (nature) or learned (nurture)?
• If intelligence is learned then the only point in testing would be to work out who needs more teaching
• If intelligence is innate and unchanging then the point of testing is to classify people
• Intelligence tests do assume that intelligence is an innate and fixed quantity, because, otherwise what is the point in doing them?
• Yerkes


  A psychologist at Harvard University who wanted to improve the status of psychology as a 'soft' science by demonstrating that it could be as objective and quantifiable as the other scientific disciplines
• Yerkes believed that intelligence was inherited and therefore could not be changed (due to nature)
• With the outbreak of WW1, Yerkes developed the idea that it might be possible to use recruits for the American army as a source of sufficient data to show that intelligence testing was scientific
• The Gould study is not a piece of empirical research, it is an edited extract from Gould's (1981) book, 'The Mismeasure of Man' in which he traces the history of the measurement of human intelligence
• The study looks at the history of Robert M. Yerkes' intelligence testing of recruits for the US army in WW1, and his attempt to establish psychology as a scientific discipline
• 1.75 million army recruits in the USA during WW1 were included in the sample, which included White Americans, 'Negroes' and European immigrants
• Army Alpha Test


  1. Designed for literate recruits, consisted of 8 parts including analogies, filling in sequences etc.

  2. Required a good basic understanding of English language skills and literacy

  3. Was extremely biased as it assumed familiarity with American culture
• Army Beta Test


  1. Designed for illiterate recruits or those who failed the Alpha Test, consisted of 7 picture completion tasks

  2. The pictures were culturally specific and would have been extremely difficult to complete without knowledge of the items
• Individual Spoken Examination


  Recruits who failed the other two tests were supposed to be given this, but it rarely happened
• Every individual was given a Grade from A to E, with plus and minus signs, to indicate their suitability for different army roles
• There were numerous problems with the administration of the tests, including inconsistencies in assigning recruits to the appropriate test
• The data was analysed by E.G. Boring, Yerkes' lieutenant, who manipulated the results
• The data showed that European immigrants could be graded by their country of origin, with the darker people of Southern Europe and the Slavs of Eastern Europe being less intelligent than the fair people of Western and Northern Europe
• White Americans had a mental age of a 13 year old, indicating that the country was 'a nation of morons'
• The black man had an average mental age of 10.41, but the lighter the skin colour the higher the scores
• The tests had a large impact on officer screening, with two thirds of the men who had been promoted being those who had taken the tests and achieved good results
• The 'fact' that the average mental age of Americans was 13 and the differences in racial and national groups' intelligence levels led to the Immigration Restriction Act of 1924, which severely limited immigration from southern and eastern Europe
• Gould makes it clear that more recent census data from 1920 was not used as the basis for the immigration quotas, as it would have allowed more southern and eastern European immigrants into the US
• The immigration restrictions had horrendous consequences, as they prevented many Jews from escaping persecution before the start of WWII
• The tests cannot be seen as valid or reliable, as intelligence is a very complex construct that needs to be assessed holistically
• The results of Gould's analysis would imply that intelligence is not innate, but that it is actually learned
• Language communicates directly an individual's thoughts to another person
• Words can reveal significant insights about psychological functioning
• Underlying cognitive and emotional processes can be revealed through subtle patterns in word choice
• There has been little examination of the speech associated with psychopaths
• Studies have shown psychopaths to exhibit a wholly selfish orientation and profound emotional deficit
• This study was the first to examine the specific qualities of psychopathic language using sophisticated statistical text analysis tools
• Psychopathy was measured using the Psychopathy Checklist Revised (PCL-R)
• The study used semi-structured/open-ended interviews to gather data on the language of psychopaths and non-psychopaths who had committed murder
• The sample consisted of 52 male murderers (14 psychopathic, 38 non-psychopathic) incarcerated in Canadian correctional facilities
• Procedure


  1. Participants underwent a psychopathy assessment using the PCL-R

  2. Participants were interviewed and asked to describe their homicide offences in detail

  3. The narratives were transcribed and analysed using the Wmatrix corpus analysis programme and the Dictionary of Affect in Language (DAL) software
• Findings


  • No significant difference in the average number of words produced by psychopaths and controls
  • Psychopaths produced more subordinating conjunctions, indicating more straight forward, cause-and-effect thinking
  • Psychopaths used more language related to basic physiological needs like money, while non-psychopaths used more language related to social needs
  • Psychopaths' speech contained more disfluences, suggesting they found describing the emotional event difficult
  • Psychopaths used more past tense verbs, indicating psychological distancing from the crime