1. Research indicates that observers do not always estimate the pain of others accurately. Often, pain is underestimated. Given the important implications this may have for the management of pain (e.g. undertreatment), more insight into the process of pain estimation is required. According to the empathy-model of Goubert and colleagues (2005) 1, the estimation of the pain is an important aspect of the sense of knowing another person in pain. Three factors influence this sense of knowing: 1) bottom-up variables (characteristics of the person in pain), 2) top- down variables (characteristics of the observer), and 3) contextual factors. A preliminary study will be presented. The study focuses on three top-down variables: observer’s catastrophic thinking, dispositional empathy and psychopathy. We hypothesized that higher levels of catastrophic thinking and dispositional empathy are associated with more accurate estimation of pain and higher levels of psychopathy with a less accurate pain estimation. Participants: 33 female student dyads Measures: Dutch version of the Pain Catastrophizing Scale ( PCS; Sullivan, Bishop, & Pivik, 1995 2 ); Empathy Quotient ( EQ; Baron-Cohen & Wheelwright, 2004 3 ) and Hare Self-Report Psychopathy Scale-III ( SRP-III; Paulhus, Hemphill, & Hare, in press 4 ). Procedure: Observer and observed person were seated in adjacent rooms. The observer watched the facial expressions of the observed person on a television screen (see Figure 1). There were 24 trials, of which on 6 trials an electric shock at tolerance level was administered to the observed person. For each trial, observers were requested to indicate whether the observed person received an electric shock or not. On the computer screen, observers could see when a trial could be expected. Observers filled in the questionnaires. Data-analysis: Using signal detection theory methods, observers’ sensitivity (d’) and response bias (C) for perceiving other’s pain were calculated. Sensitivity refers to the observer’s ability to discriminate between different levels of pain. The response bias refers to the tendency of the observer to impute pain to the observed person, independent of whether the observed person actually received a pain stimulus or not. Correlation analyses revealed significant negative correlations between the scores on psychopathy both with the sensitivity and the response bias (Tabel 1). No significant correlation were found for the scores on dispositional empathy, nor for the scores on catastropic thinking. INTRODUCTION De Ruddere, L.¹*, MSc, Goubert, L.¹, PhD, Uzieblo, K. 2, PhD, Vervoort, T.¹, PhD, Caes, L.¹, MSc, Crombez, G.¹, PhD 1 Department of Experimental-Clinical and Health Psychology, Ghent University, Belgium 2 University College Antwerp, Lessius, Belgium Corresponding author. Lies De Ruddere, E-mail: Lies.DeRuddere@Ugent.be Why pain is not taken seriously by others: a signal detection analysis METHOD observer camera Computer screen observed person shocker TV Fig. 1. Schematic presentation of the experimental setting. Psychopathy (SRP-III) Dispositional Empathy (EQ) Catastrophic Thinking (PCS) d’-.424*.071-.101 C-.541**-.050.014 Higher scores on psychopathy were associated with a less accurate pain detection and a greater response bias: the more the person had psychopathic traits, the less she was able to discriminate between pain and no-pain trials and the more she was tended to indicate that the other person received a pain trial. Higher scores on catastrophic thinking and dispositional empathy were not related to sensitivity, nor to response bias. These findings suggest that there is no relation between catastrophic thinking and the pain evaluation nor between dispositional empathy and the pain evaluation. The results should be interpreted with caution given the fact that this study is a preliminary one and some methodological shortcomings should be taken into account. First, the sample size was small: only 33 student dyads participated the study. Second, several observers had a hit rate of 1 and/or a false alarm rate of 0, necessitating an adjustment of the scores to allow a signal detection analysis. Given the arbitrariness of the new values, one should be cautious in drawing any conclusions. Third, only 24 trials per dyad were used, limiting the validity of the signal detection results. Although the results of this study do suggest an influence of psychopathy upon the estimation of pain, other important bottom-up, top down and contextual determinants deserve further attention in subsequent research. First, the influence of personal characteristics of the person in pain would be an interesting factor to investigate. We can expect observers to rate the pain of a person differently according to whether this person has positive or negative character traits. Second, based upon the theory of cognitive conservatism, we can expect an influence of the information about the pain that is experienced. Information that does not fit within a strict biomedical perspective is expected to be associated with a greater underestimation of the pain. Finally, the influence of the presence of cues that suggest secondary disease-benefits of the pain is a challenging factor that need to be considered in future research. Based upon the evolutionary perspective, we can expect observers to underestimate the pain to a greater extent when there is a suspicion of deception. References 1 Goubert et al. (2005). Facing others in pain: the effects of empahty. Pain, 118, 285-288. 2 Sullivan, M.J.L., Bishop, S.R., & Pivik, J. (1995). The Pain Catastrophizing Scale: Development and Validation. Psychological Assessment, 7, 524-532. 3 Baron-Cohen, S., & Wheelwright, S. (2004). The empathy quotient: An investigation of adults with Asperger syndrome or high functioning autism, and normal sex differences. Journal of Autism and Developmental Disorders, 34, 163-175. 4 Paulhus, D. L., Hemphill, J. F., & Hare, R. D. (in press). Scoring manual for the Hare Self-Report Psychopathy Scale-III. Toronto: Multi-Health Systems. DISCUSSION Tabel 1. Correlations for both the sensitivity (d’) and the response bias (C) with the total scores of the SRP, the EQ and the PCS. ACKNOWLEDGEMENTS This research is supported by the Fund for Scientific Research, Flanders (F.W.O.). RESULTS