Abstract
P. W. Cheng's (Citation1997) power PC theory of causal induction proposes that causal estimates are based on the power (P) of a potential cause, where P is the contingency between the cause and effect normalized by the base rate of the effect. Most previous research using a standard causal probe question has failed to support the predictions of the power PC model but recently Buehner, Cheng, and Clifford (Citation2003) found that participants responded in terms of causal power when probed with a counterfactual test question, which they argued prompted participants to consider the base rate of the effect. However, Buehner et al. framed their counterfactual question in terms of frequency, a factor that has been demonstrated to decrease base rate neglect in judgements under uncertainty. In the experiment reported here, we sought to disentangle the influence of counterfactual and frequency framing of the probe question to determine which factor is responsible for encouraging responses in terms of causal power.
Acknowledgments
The research described here was supported by a grant from the United Kingdom Biotechnology and Biological Sciences Research Council. The work is part of the programme of the ESRC Centre for Economic Learning and Social Evolution, University College London. We would like to thank Marc Buehner for his assistance in preparing the task instructions and questions.