Temporal and causal order effects in thinking about what might have been Susana Segura and Pablo Fernandez-Berrocal University of Malaga, Malaga, Spain Ruth M.J. Byrne University of Dublin, Trinity College, Dublin, Ireland When people think counterfactually about what might have been different for a sequence of events, they are influenced by the order in which the events occurred. They tend to mentally undo the most recent event in a temporal sequence of two events. But they tend to mentally undo the first event in a causal sequence of four events. We report the results of two experiments that show that the temporal and causal order effects are not dependent on the number of events in the sequence. Our first experiment, with 300 participants, shows that the temporal order effect occurs for sequences with four events as well as for sequences with two events. Our second experi- ment, with 372 participants, shows that the causal order effect occurs for sequences with two events as well as for sequences with four events. We discuss the results in terms of the mental rep- resentations that people construct of temporal and causal sequences. Thinking about what might have been requires the mental comparison of an actual situation with a simulated alternative (e.g., Kahneman & Miller, 1986; Kahneman & Tversky, 1982). Counterfactual thinking is pervasive in everyday thoughts, perhaps especially following nega- tive outcomes (Roese, 1997). Counterfactual thoughts may play a role in many cognitive pro- cesses such as causal judgements (e.g., Roese & Olson, 1995), deductive reasoning (e.g., Johnson-Laird & Byrne, 1991, in press), and creativity (e.g., Hofstadter, 1985), and they may help people to learn and prepare for the future (e.g., Roese, 1994). They may also play a role in emotional processes such as guilt (e.g., Miller & Gunasegaram, 1990) and regret (e.g., Gilovich & Medvec, 1994; Landman, 1987). When people think counterfactually, they tend to focus on particular sorts of events to mentally undo. For example, they tend to alter actions rather than failures to act (Kahneman & Requests for reprints should be sent to Dr Susana Segura, Departamento de Psicología Básica, Facultad de Psicología, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain. Email: s_segura@uma.es We thank Phil Johnson-Laird, Mark Keane, Rachel McCloy, Ronan Culhane, Alessandra Tasso, Clare Walsh, Alice McEleney, and Michael Morris for helpful discussions of the temporal order effect. The results of some of the experiments were presented at the mental models in reasoning conference at Madrid, Spain, in 1998, and at the First Conference on Spanish and Portuguese Psychology at Santiago de Compostela, Spain, in 2000. Ó 2002 The Experimental Psychology Society http://www.tandf.co.uk/journals/pp/02724987.html DOI:10.1080/02724980244000125 THE QUARTERLY JOURNAL OF EXPERIMENTAL PSYCHOLOGY, 2002, 55A (4), 1295–1305