Evaluating Causal Explanations

1. Evaluating Causal Explanations

2. Fallacies in Causal Reasoning Confusing Correlation and Cause a.Coincidence Example Holland's birthrate and the number of stork's nesting in chimneys. Example An individual's level of literacy and their participation in volunteer work b.Symmetry Example           time spent in hospital and risk of death.

3. c.Common cause Example           El Nino effect and drought in Australia Example shoe-size and quality of handwriting have a common cause — maturity. d.Reflexivity Example chicken and egg e.Insignificance

4. Similar fallacy with Sufficient Condition Test and Necessary Condition Test. Example homosexual males have a certain brain property X. (women and homosexual men registered a reaction in the anterior hypothalamus when tested with 4, 16-androstadien-3-one, but women and heterosexual men did not.) Post Hoc Ergo Propter Hoc ‘After this therefore because of this’

5. Evaluation of Explanations a.Plausibility. b.Power. c.Simplicity. ‘Occam’s Razor’ Example Ptolemaic and the Copernican theories.

6. d.Generality. Example South America & Africa – Continental Drift - distribution of flora and fauna. e.Modesty. Example Continental Drift - What could be more solid than a mountain range? Example Lyell’s geology

7. Criticism of Theories a.Is there something to explain? Example Global warming – are the Pacific islands sinking? b.Is there a plausible alternative theory? Example AGW again - solar activity

8. c.Are the theory’s predictions good? Example Michelson-Morley experiment Example AGW again - warming will occur first in the atmosphere d.Does the defence of the theory seem rather ad hoc? Example Epicycles in Ptolemaic astronomy. Saving the appearances. e.Is the theory testable?