1. The role of emotions in the omission vs commission dilemmas Raffaella Di Schiena Guglielmo Bellelli University of Bari (Italy) Tony Manstead Univesity of Cardiff (UK) Marcel Zeelenberg University of Tilburg (NL)

2. Omission bias The tendency to prefer inactive over active options, even when this leads to greater risks or worse outcomes (Ritov & Baron, 1990)

3. Theoretical background The vaccination dilemma (Ritov & Baron, 1990): “Imagine you are parent of a child who is under three years old. In the country you live in there is an epidemic flu that can be fatal for children at this age (…) 10 out of 10,000 children can die because of the flu. A vaccine for this kind of flu has been developed and tested (…). However, the vaccine is also risky. Because of its side effects, 5 out of 10,000 vaccinated children can die. Excluding these, neither the vaccine nor the flu have any long term effects” “What would you choose in this situation?” 20%-40% choose the omission “Which is the maximum level of risk from the action you would be willing to accept?” Those who decide to act easily change their mind for slightly higher risk from the action, but still lower than risk from the omission

4. Why is OB important? Theoretical reasons: It violates rationality axioms, according to which a rational choice has to be based on expected consequences, like in E-U type models of choice (Von Neuman & Mortestern, 1947). Omission choice is a non-consequential choice (Baron, 1994) Practical reasons: Mainly public health concerns. OB in real vaccination choices (Asch et al.,1994; Wroe et al., 2005) OB in physicians’clinical practice (Aberegg, et al., 2005)

5. Additional evidence about OB in choice: closing the debate? (3 studies) (R. Di Schiena, G. Bellelli, A.S.R. Manstead, M. Zeelenberg) Emotion in OB: Where is it? (2 studies) (R. Di Schiena, G. Bellelli, M. Zeelenberg) OB in health decision making: The role of emotion and trust in health care (2 studies) (R. Di Schiena, G. Bellelli, A.S.R. Manstead) Overview

6. Additional evidence about OB: Closing the debate? R. Di Schiena, G. Bellelli, A.S.R. Manstead, M. Zeelenberg

7. Criticisms (Connolly & Reb, 2003). Fluctuating percentages of Ss choosing the omission do not necessarily imply that there is a bias towards the omission, as they can be due to other factors. Is it an experimental artefact, induced by the vaccination scenario? Study 1 Study 2 & 3

8. Study 1 Hypothesis: If there is a bias towards the omission, then… Individuals might choose irrationally only when the irrational choice is an omission Individuals who choose to act might be less confident in the choice made than those who didn’t Those who choose the omission neglect consequences and rely more on the fact that one of the two options is an omission They might do that, controlling for attitude, previous experiences and/or other elements

9. Study 1 Three between Ss conditions: 1) Not to vaccinate (10/10000) VS Vaccinate (5/10000) (N = 48) 2) Not to vaccinate (6/10000) VS Vaccinate (5/10000) (N = 49) 3) Vaccination 1 (10/10000) VS Vaccination 2 (5/10000) (N = 48) Main Measures: Choice behaviour Maximum level of risk accepted from the action (MLRA) Additional measures: Risk information Frame of the two options Attitude towards vaccination Previous experiences Other elements

10.  The number of Ss rationally choosing the less risky option was significantly higher in the Action vs Action condition (χ2 = 27.667; df = 2; p <.005)  A specific comparison between the two Action vs Omission conditions revealed a non significant difference (χ2 = 1.752; df = 1; p =.186 )  Results on MLRA: Vaccinators where less confident in the choice made t (47) = 3.86, p <.005. Riskier option Less risky option Study 1 Results on behaviour

11. Study 1 Questionnaire results split by behaviour Vaccinators vs non Vaccinators Importance of risk: p <.005 Act5-Act10Act5-Om10 Act5-Om6 Importance of frame: p <.001 VaccinatorsNon Vaccinators Vaccinators …attitude, previous experiences and other elements didn’t significantly impact the choice

12. Study 1 The OB is real!  Individuals chose the riskier option only when this was an omission  Vaccinators were less confident in the choice made than Non- vaccinators  The omission choice was based on a higher consideration of aspects that have nothing to do with expected consequences  Omission choice can not be explained by attitude, previous experienes and so forth Conclusions

13. Study 2 Hypothesis: Ob is a general effect if… In other scenarios frequency of omission is significantly different from 0 and not significantly different from the vaccination scenario Vaccination scenario (as control) Managerial scenario: Imagine you are the owner of a big company, which is going through a very difficult crisis. (…) 60% risk of bankruptcy if you do not do anything (…) If you implement a recovery plan, it has a failure rate of 45%. Investment scenario: Imagine you have invested all your savings in stocks of company A, which is going through a very difficult crisis. (…) 60% risk of loosing all your savings. (…) If you switch, the risk of loosing is 45%.

14. Study 2 VaccinationInvestmentManagerial 31.2%24.7%21.5%  For each scenario: Frequency of omission was significantly different from 0 exact binomial p (one-tailed) <.001 MLRA for vaccination: t (86) = 5.10, p <.001 MLRA for investment: t (19.16) = 7.14, p <.001 MLRA for managerial: t (21.77) = 8.25, p <.001  Across scenarios: Frequency of omission did not differ significantly Cochran-Q, ns N = 92 Students Scenario order counterbalanced

15. Study 2 Conclusions Ob is a general effect across different domains Concern: the choice situation is not relevant for a students’ sample? Study 3

16. Study 3 Replication of Study 2 with relevant samples Hypothesys: The same as in Study 2 Materials and procedure: The same as in Study 2 (investment and managerial choices were used as a unique choice) Participants: 75 Financial advisors confronted with economic scenarios 64 Parents of children in vaccination age confronted with vaccination scenario

17. Study 3  For each scenario: Frequency of omission was significantly different from 0 (25%) exact binomial p (one-tailed) <.001 MLRA for economic: t (12.93) = - 5.48, p <.001 MLRA for vaccination scenario: t (55.02) = - 4.35, p <.001  Across scenarios: Frequency of omission was significantly higher in the vaccination choice χ² (1, N = 139) = 5.32, p <.05. VaccinationEconomic 20%34.4%

18. Additional evidence about OB in choice: Closing the debate? The empirical test yield positive results: There is an irrational tendency to favour the omission that is not due to other factors over a bias towards it This effect is general across domains, but to a different extent Future work: Understand why there are different omission tendencies for different scenarios May be the emotional vivdness of the situation?

19. The role of emotion in the OB: Where is it? R. Di Schiena, G. Bellelli, M. Zeelenberg

20. Theoretical background Emotion and Decision Making Emotionality of the process: Choices can be based on gut feelings, instead of a thorough analysis (Epstein & Pacini, 1999) Anticipated emotions: Decisions can be aimed at avoiding future regret, instead of simply maximizing possible gains (Zeelenberg, 1999) Experienced emotions: Negative emotions elicited by a difficult choice situation can make individuals adopt an avoidant behavior (Luce, 1998) Risk itself can evoke anxiety and fear that make people adopt a non consequential choice (Loewenstein, Weber, & Hsee, 2001).

21. Study 1 OB in a dual process perspective Theoretical background: According to dual-process theories, decision makers process the available information relying on the analytical system or on the affective-experiential system (Epstein & Paccini, 1999; Slovic et al., 2004) Evidence shows that, when they activate an affective-experiential process, irrational choices are more likely (Finucane et al., 2000) Hypothesys: When relying on the affective-experiential system, Ss will show a higher OB

22. SCENARIO Think aloud CHOICE + MLRA SCENARIO CHOICE + MLRA Materials and procedure Time pressure (N = 60) Control (N = 58) Scenario: Immagine you have a serious brain infection that can bring about permanent brain damage (…). Omission: Not to have the intervention (20% risk of brain damage) Action: To have an intervention that would stop the brain infection (15% risk of brain damage) Conditions: Think aloud Rational Experiential Inventory (Epstein & Pacini, 1999) as control measure

23. Study 1 Results on MLRA Time pressure (M = 20.28); Control (M = 29.06) (p <.05) 31% 25% Time pressureControl Results on behaviour Manipulation check Verbal protocols (???) R.E.I. scores were equally distributed

24. Study 2 Anticipated regret and OB Theoretical background: Some scholars suggest that individuals prefer the omission because they expect to feel less regret in case of negative outcome (Anderson, 2003) Evidence shows that, being consequences equal, individuals regret more the action than the omission (Landman, 1987; Kahneman & Tversky, 1982)

25. Study 2 Anticipated regret and OB Hypothesys: If anticipated regret caused OB, then… In the choice phase: When possible regret is more salient, Ss are more likely to choose the omission In the Post-choice Pre-resolution: Ss are expected to feel more anxious if they have choosen the action In the Post-choice Post-resolution: If the outcome is negative, Ss are expected to regret more when they have chosen the action than when they have chosen the omission (Landman, 1987; Kahneman & Tversky, 1982)

26. SCENARIO Think aloud CHOICE + MLRA OUTCOME SCENARIO Think aloud Anxiety (2 measures) Regret CHOICE + MLRA Study 2 Scenario: The same as in Study 1 Conditions: Expected feedack (N=55) Control (N=58)

27. Results on behaviour Feedback (M = 21.68); No feedback (M = 29.87) (p =.063) Results on MLRA 29% 20% FeedbackControl Study 2

28. Study 1 Results on emotion measures  Post-choice pre-resolution: Ss who decided to act where more anxious than those who omitted on both the anxiety measures (p <.05 and p =.052)  Post-choice post-resolution: Those who acted felt more regret than those who did not act (p<.005);  Manipulation check: Verbal protocols (???)

29. Relying on the affective-experiential system induces a higher OB, but this effect is weak Regret anticipation induces a higher OB, but the effect is weak as well Weak manipulations? Small samples? The role of emotion in the OB: Where is it?

30. OB in health decision making: The role of emotion and trust in health care R. Di Schiena, G. Bellelli, A.S.R. Manstead

31. Strange results of previous studies: In the brain infection situation, many Ss did not only prefer the action, but even wanted to have the intervention when it was riskier than doing nothing (action bias, Patt & Zakhauser, 1997)

32.  Decision making as emotion focused coping (Luce, 1998): When facing a risky decision, Ss are motivated to cope with negative emotions the risk evokes, and this can push them into acting paradoxically… Sometimes this could bring about OB… But… coping goals are mediated by subjects’ beliefs Ss’ beliefs that physician or health-care system is trustworthy can interact with the effect of emotion (Benin et al., 2006). Theoretical background

33.  Hypothesis: When the choice situation is highly emotional: - Ss with high trust will tend to favour the action, even when it’s riskier (ACTION BIAS) - Ss with low in trust will tend to favour the omission, even when it’s riskier (OMISSION BIAS)  Trust manipulation by priming: Ss are provided with a page illustrating the health care achievements (the dramatic occurrence of medical errors), and a story, in a box, as vivid example  Emotionality manipulation by different instructions: High Em.: Try to imagine vividly how you would feel in this situation and how this could affect your life Low Em.: Try to be objective and detached, in order to give your acquaintance the best advice

34. Condition 1: High emotionality High Trust Condition 2: High emotionality Low Trust Condition 3: Low emotionality High Trust Condition 4: Low emotionality Low Trust  Exp 1: Action less risky than Omission  Exp 2: Action as risky as Omission Condition 5: High emotionality High Trust Condition 6: High emotionality Low Trust Condition 7: Low emotionality High Trust Condition 8: Low emotionality Low Trust (N= 96) (N= 120)

35. 3 scenarios in counterbalanced order  Brain surgery: (cfr. previous studies)  Vaccination scenario: (cfr. previous studies) Slow growing cancer: Omission: risk of dying from the cancer: 20% Action: To have chemotherapy that would cure your slow growing cancer permanently, but implies a risk of dying from a myelodysplastic syndrome: 15% (20%) Materials

36.  Dependent measures: Frequency of omission MLRA from the action (and from the OMISSION in exp. 2) Option evaluation  Emotionality manipulation check: PANAS scale (Watson, Clark, & Tellegen, 1988)  Trust manipulation check: four items right after the manipulation  Covariate: A revised version of the Trust in Physician Scale (TPS) (Anderson & Dedrick, 1990) Measures (Exp. 1 & 2)

37. Exp. 1: High trust, high emotion: High trust, low emotion: Low trust, low emotion: Low trust, high emotion: OB Exp. 2: High trust, high emotion: preference for action + act. bias High trust, low emotion: preference for action Low trust, low emotion: preference for omission Low trust, high emotion: preference for omission + om. bias _ + Hypothesys

38. Provisional results… (exp. 1 and 2) Both manipulations were effective: Emotionality (.018 < p <.080) Trust manipulation (p <.01)

39. Provisional results… (exp.1 and 2) Log linear analysis on frequencies doesn’t show any significant interaction ANOVA on continuous DVs doesn’t show any significant interaction However… There is a main effect of trust in the expected direction, that is never significant but stable across scenarios and dependent measures In Exp. 2, brain surgery scenario, there was also an interaction effect between emotionality and trust, that was not significant but stable across all of the dependent measures

40. General conclusions There is an OB and is general across domains, so we still need to be concerned about it Evidence about the role of emotions is non significant but in the expected direction and reliable..a fruitful direction? What is needed? Larger samples and stronger manipulations!! The pure “emo-cognitive” perspective is not enough, since domain specific factors are surely involved (i.e. Trust in health care; manager are expected to act) Future work should deepen the interaction btween these factors and the emotions

41. Many thanks for your attention