Evaluating ToP: Empirical Validity

• Empirical Validity


  A good theory will generate predictions, so it can be empirically tested and shown to be valid.

  • Should be free from systematic error
  • How well the test measures what it supposed to measure?
  • Face Validity: Does the test look like measure what it claims to measure?
  • Construct validity: The extent to which a test captures a specific theoretical construct or trait.
  • Predictive validity: Does a test accurately predict a criterion that will occur in the future.
• Neuroticism


  • The stability of neuroticism increases with age from adolescence through adulthood (Roberts & DelVecchio, 2000).
  • Mean neuroticism scores peak in late adolescence and decline moderately through adulthood (McCrae & Costa, 2003).
  • Neuroticism scores tend to be somewhat higher among individuals with lower socioeconomic status (Judge, Higgins, Thoresen, & Barrick, 1999).
• What factors would determine an individuals level of neuroticism?

  Substantially heritable with 50%–60% of the variance in neuroticism scores estimated to be attributable to genetic factors.

  • Lahey recognises that there must be environmental causal influences on neuroticism
  • BUT we don’t have good evidence pointing towards what these might be.
  • Researc is based on retrospective studies (asking individuals with high vs. low levels of neuroticism to look back and reflect on their early life experiences)
  • Problematic because all sorts of biases can creep into people’s recollection.
• Effect Sizes (Cohen’s d) From Two Meta-Analyses of Associations Between Neuroticism and Axis I and Axis II Disorders

  
• Predictive utility of neuroticism for mental health outcomes

  Utility of neuroticism in predicting first episodes of major depression was evaluated in

  • longitudinal study
  • 1,733 twins from female–female pairs
  • 1,862 twins from male–male pairs

  The study excluded participants who had already experienced an episode of depression by the time neuroticism was measured.

  • each 1 standard deviation (SD) unit difference in higher neuroticism scores was associated with:
  • 90%– 100% ↑ in odds of developing MDD for the first time during the next 12 months in women
  • 85% ↑ in the odds of doing so in men