Wins above replacement: Responsibility attributions as counterfactual replacements - eScholarship (2014)

Wins above replacement: Responsibility attributions as counterfactual replacements Tobias Gerstenberg 1 (tger@mit.edu), Tomer D. Ullman 1 (tomeru@mit.edu), Max Kleiman-Weiner 1 (maxkw@mit.edu) David A. Lagnado 2 (d.lagnado@ucl.ac.uk) & Joshua B. Tenenbaum 1 (jbt@mit.edu) 1 Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 Perceptual and Brain Sciences, University College London, London WC1H 0AP 2 Cognitive, Abstract In order to be held responsible, a person’s action has to have made some sort of difference to the outcome. In this pa- per, we propose a counterfactual replacement model accord- ing to which people attribute responsibility by comparing their prior expectation about how an agent was going to act in a given situation, with their posterior expectation after having observed the agent’s action. The model predicts blame if the posterior expectation is worse than the prior expectation and credit if it is better. In a novel experiment, we manipulate peo- ple’s prior expectations by changing the framing of a struc- turally isomorphic task. As predicted by our counterfactual replacement model, people’s prior expectations significantly influenced their responsibility attributions. We also show how our model can capture Johnson and Rips’s (2013) findings that an agent is attributed less responsibility for bringing about a positive outcome when their action was suboptimal rather than optimal. Keywords: counterfactuals; responsibility; Bayesian infer- ence; attribution; theory of mind. Introduction How do we hold others responsible for their actions? There is a strong intuition that someone can only be held responsible if what they did made a difference to the outcome. There are at least two ways to assess the extent to which a person made a difference to the outcome. The first way is to consider an action-centered contrast and compare the actual action a per- son took with alternative actions she could have taken. Imag- ine a Dr. Smith who administers a treatment that causes a patient to suffer from severe side effects. If there were al- ternative options that would have led to a better outcome for the patient, we might blame Dr. Smith for the choice she made. In contrast, if we believe that the alternative options would have led to even worse side-effects, we might think Dr. Smith’s decision is creditworthy. The second way to as- sess difference-making is to consider a person-centered con- trast and compare what a person did with what other persons would have done in the same situation. We might not blame Dr. Smith for the negative outcome – even if there was an al- ternative treatment that would have been better for the patient – if we believe that other doctors would have prescribed the same treatment in her place. In the law, we find both action-centered and person- centered contrasts. According to the “but-for test”, a defen- dant’s action is deemed a factual cause of a negative outcome if the outcome would not have occurred but for his action (Hart & Honor´e, 1959/1985). According to the “reason- able man test”, whether a person’s behavior is deemed negli- gent depends on what a reasonable man would have done in the given situation (Schaffer, 2010). Another example of a person-centered contrast is found in baseball, where a statis- tic called “Wins Above Replacement” (WAR) expresses the additional number of wins a player contributes to the team’s success, compared to the estimated number of wins the team would have achieved with a replacement (Jensen, 2013). Previous work in psychology has shown that both action- centered and person-centered counterfactual contrasts influ- ence responsibility attributions. For example, according to Brewer (1977), responsibility attributions are (i) negatively related to the subjective probability that the outcome would have occurred in the absence of the person’s action, and (ii) positively related to the subjective probability that the out- come will occur given the person’s action (see also Petro- celli, Percy, Sherman, & Tormala, 2011; Spellman, 1997). Fincham and Jaspars (1983) showed in a series of experi- ments that responsibility attributions are also significantly in- fluenced by the subjective degree of belief that another person would have acted in the same way as the protagonist did in the given situation. In this paper, we propose a formal model of responsibil- ity attribution that is based on the person-centered contrast. Inspired by the “reasonable man test” and WAR, we model people’s intuitive judgments of blame and credit in terms of counterfactual replacements. Our counterfactual replacement model predicts that people assign blame or credit by compar- ing their prior expectations about how likely a person is to bring about a positive outcome in a given situation, with their posterior expectations after they have observed the person’s action. The more a person’s action changes our expectation for the better, the more credit we give that person for their action (cf. Ajzen & Fishbein, 1975). Conversely, we blame a person to the extent that our expectations decrease after hav- ing observed their action. A key advantage of our model over action-centered ac- counts is the natural way in which it captures how intentional and accidental actions are deserving of different degrees of responsibility (Lagnado & Channon, 2008). Our model pre- dicts that responsibility attributions are a function of the ex- tent to which the observation of a person’s action leads us to change our expectations about their future behavior. In- tentional actions potentially carry rich information about the person’s invariant character traits that are predictive of their future behavior. Accidental actions, in contrast, usually carry less information about the person’s character (Heider, 1958). By explicitly modeling prior expectations about a person’s characteristics, our model incorporates normative considera- tions for action from action-centered accounts of responsi- bility attribution. Most situations in which questions of re-