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Moral Intuitions and Emotions: Evaluating the Evidence

We have considered Schnall, Haidt, Clore, & Jordan (2008) as evidence for the idea that moral intuitions rely on the Affect Heuristic (as Sinnott-Armstrong et al (2010) propose). Whenever we encounter potential evidence, we should ask two questions of it. First, is it really evidence? Second, is it sufficient to justify us in accepting the claim we take it to be evidence for?

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On this course you will be evaluating quite a lot of scientific evidence. As this is not something you are required to be familiar with doing before taking the course, I shall go through the process of evaluation quite slowly for the first time.

Step 0: Never Trust a Philosopher

This includes me, your lecturer. Always evaluate the evidence for yourself.

Step 1: Is It Really Evidence?

When faced with a potential piece of evidence, there are three questions you should always ask:

  1. Has the study been successfully replicated?
  2. Are there similar studies? If so, are the findings convergent?
  3. Has the study featured in a review? If so, does the review broadly support the findings of this study?

Before we rely on the findings of a study, we should ideally have positive answers to these questions. (Perhaps we do not need a successful replication, but if so there should at least not be unexplained failures to replicate the study.)

In the case of Schnall et al. (2008), the answers to these questions are quite complicated:

  1. Experiment 1 of Schnall et al. (2008) is actually a successful conceptual replication of Wheatley & Haidt (2005).

    Ugazio, Lamm, & Singer (2012) report an unsuccessful attempt to replicate Experiment 1 of Schnall et al. (2008). Although this failed replication may weaken our confidence in Schnall et al. (2008)’s findings, note that, as Ugazio et al. (2012, p. 589) report, there is an extraneous weakness in attempted replication which explain may the failure to replicate.[1]

    Johnson et al. (2016) report an convincing failure to replicate Experiment 3 (the one where disgust is induced by having participants recall a disgusting event in their lives.)[2]

  2. Yes, there are similar studies (e.g. Eskine, Kacinik, & Prinz, 2011); yes, these findings are convergent with those of Schnall et al. (2008).

  3. Yes, the study has featured in at least one review (Chapman & Anderson, 2013, p. 313). Yes, this review does broadly support the findings of Schnall et al. (2008).[3] But, as you can see below, there are also reviews which support a view incompatible with these findings.

At this point, it seems we can take the findings of Schnall et al. (2008) as evidence.[4] However, a more recent meta-analysis by Landy & Goodwin (2015) draws the opposite conclusion,[5] as does a recent study (Jylkkä, Härkönen, & Hyönä, 2021; thank you Julina!). Authoritative commentaries by Giner-Sorolla, Kupfer, & Sabo (2018, pp. 261–2) and Piazza, Landy, Chakroff, Young, & Wasserman (2018) conclude that the available evidence is not strong.[6] Indeed, Piazza et al. (2018, p. 54) argue that ‘robust evidence is lacking for a unique effect of disgust on moral judgment.’

What should we conclude? Without closer evaluation of more experimental findings (which is surely worthwhile, although not for everybody), we should be cautious in taking Schnall et al. (2008) or similar studies as providing strong evidence that experimentally induced extraneous disgust makes people harsher in their moral judgements.

We should not infer that emotions and feelings do not influence moral intuitions at all. There are other ideas about how disgust and other feelings could influence emotion which are supported by other sources of evidence (for instance, Piazza et al., 2018).


How, if at all, do emotion or feelings influence moral intuitions? Since the Affect Heuristic provides a direct and bold answer to this question, we have been concerned to identify and evaluate evidence for Affect Heuristic. One key piece of evidence cited by Sinnott-Armstrong, Young, & Cushman (2010) is Schnall et al. (2008). Although initially convincing, considering a wider range of research indicates that this is probably not strong evidence for the Affect Heuristic.

This may motivate us to consider other possible sources of evidence for the Affect Heuristic. Or it may motivate us to consider other theories about how emotions or feelings influence moral intuitions.[7]

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More information about asking questions.


Affect Heuristic : In the context of moral psychology, the Affect Heuristic is this principle: ‘if thinking about an act [...] makes you feel bad [...], then judge that it is morally wrong’ (Sinnott-Armstrong et al., 2010). These authors hypothesise that the Affect Heuristic explains moral intuitions.
A different (but related) Affect Heurstic has also be postulated to explain how people make judgements about risky things are: The more dread you feel when imagining an event, the more risky you should judge it is (see Pachur, Hertwig, & Steinmann, 2012, which is discussed in The Affect Heuristic and Risk: A Case Study).
moral intuition : According to this lecturer, a person’s intuitions are the claims they take to be true independently of whether those claims are justified inferentially. And a person’s moral intuitions are simply those of their intuitions that concern ethical matters.
According to Sinnott-Armstrong et al. (2010, p. 256), moral intuitions are ‘strong, stable, immediate moral beliefs.’
replicate an experiment : To replicate a experiment is to attempt to repeat it with the aim of reproducing the original findings. Where the original findings are not found, it is called a failed replication.
A replication can be more or less direct; that is, it may adhere very closely to the original experiment, or it may include varations in the stimuli, subjects and settings. Very indirect replications are sometimes called conceptual replications.


Chapman, H. A. (2018). A component process model of disgust, anger, and moral judgment. In Atlas of moral psychology (Vol. 70, p. 70—80). New York: Guilford Publications.
Chapman, H. A., & Anderson, A. K. (2013). Things rank and gross in nature: A review and synthesis of moral disgust. Psychological Bulletin, 139(2), 300–327.
Chapman, H. A., Kim, D. A., Susskind, J. M., & Anderson, A. K. (2009). In Bad Taste: Evidence for the Oral Origins of Moral Disgust. Science, 323(5918), 1222–1226.
Decety, J., & Cacioppo, S. (2012). The speed of morality: A high-density electrical neuroimaging study. Journal of Neurophysiology, 108(11), 3068–3072.
Eskine, K. J., Kacinik, N. A., & Prinz, J. J. (2011). A Bad Taste in the Mouth: Gustatory Disgust Influences Moral Judgment. Psychological Science, 22(3), 295–299.
Giner-Sorolla, R., Kupfer, T., & Sabo, J. (2018). What Makes Moral Disgust Special? An Integrative Functional Review. In J. M. Olson (Ed.), Advances in Experimental Social Psychology (Vol. 57, pp. 223–289). Academic Press.
Johnson, D. J., Cheung, F., & Donnellan, M. B. (2014). Does Cleanliness Influence Moral Judgments? Social Psychology, 45(3), 209–215.
Johnson, D. J., Wortman, J., Cheung, F., Hein, M., Lucas, R. E., Donnellan, M. B., … Narr, R. K. (2016). The effects of disgust on moral judgments: Testing moderators. Social Psychological and Personality Science, 7(7), 640–647.
Jylkkä, J., Härkönen, J., & Hyönä, J. (2021). Incidental disgust does not cause moral condemnation of neutral actions. Cognition and Emotion, 35(1), 96–109.
Kumar, V. (2016). The empirical identity of moral judgment. The Philosophical Quarterly, 66(265), 783–804.
Landy, J. F., & Goodwin, G. P. (2015a). Does incidental disgust amplify moral judgment? A meta-analytic review of experimental evidence. Perspectives on Psychological Science, 10(4), 518–536.
Landy, J. F., & Goodwin, G. P. (2015b). Our conclusions were tentative, but appropriate: A reply to schnall et al.(2015). Perspectives on Psychological Science, 10(4), 539–540.
May, J. (2014). Does Disgust Influence Moral Judgment? Australasian Journal of Philosophy, 92(1), 125–141.
May, J. (2018). Regard for Reason in the Moral Mind. Oxford University Press.
McAuliffe, W. H. B. (2019). Do emotions play an essential role in moral judgments? Thinking & Reasoning, 25(2), 207–230.
Pachur, T., Hertwig, R., & Steinmann, F. (2012). How Do People Judge Risks: Availability Heuristic, Affect Heuristic, or Both? Journal of Experimental Psychology: Applied, 18(3), 314–330.
Piazza, J., Landy, J. F., Chakroff, A., Young, L., & Wasserman, E. (2018). What disgust does and does not do for moral cognition. In N. Strohminger & V. Kumar (Eds.), The moral psychology of disgust (pp. 53–81). Rowman & Littlefield International.
Schnall, S., Benton, J., & Harvey, S. (2008). With a Clean Conscience: Cleanliness Reduces the Severity of Moral Judgments. Psychological Science, 19(12), 1219–1222.
Schnall, S., Haidt, J., Clore, G. L., & Jordan, A. H. (2008). Disgust as Embodied Moral Judgment. Personality and Social Psychology Bulletin, 34(8), 1096–1109.
Schnall, S., Haidt, J., Clore, G. L., & Jordan, A. H. (2015). Landy and Goodwin (2015) Confirmed Most of Our Findings Then Drew the Wrong Conclusions. Perspectives on Psychological Science, 10(4), 537–538.
Sinnott-Armstrong, W., Young, L., & Cushman, F. (2010). Moral intuitions. In J. M. Doris, M. P. R. Group, & others (Eds.), The moral psychology handbook (pp. 246–272). Oxford: OUP.
Tracy, J. L., Steckler, C. M., & Heltzel, G. (2019). The physiological basis of psychological disgust and moral judgments. Journal of Personality and Social Psychology, 116(1), 15–32.
Ugazio, G., Lamm, C., & Singer, T. (2012). The Role of Emotions for Moral Judgments Depends on the Type of Emotion and Moral Scenario. Emotion, 12(3), 579–590.
Wheatley, T., & Haidt, J. (2005). Hypnotic Disgust Makes Moral Judgments More Severe: Psychological Science, 16(10), 780–784. Retrieved from


  1. Some of the same authors pubilshed another study in the same year (Schnall, Benton, et al., 2008). Johnson et al. (2014) attempted to replicate this other study. Those authors’ results convincingly indicate that the effect is not powerful enough to have been discovered by the original study. This is an informative failure to replicate. My recommendation is therefore not to consider (Schnall, Benton, et al., 2008) as evidence. ↩︎

  2. Johnson et al. (2016)’s primary focus is where individual variation in disgust sensitivity (as measured by private body consciousness) mediates the influence of disgust on moral judgement. They conclude that ‘written disgust manipulations did not impact moral judgments, nor was this effect moderated by individual differences in sensitivity to internal bodily sensations’ (Johnson et al., 2016, p. 6). ↩︎

  3. Chapman & Anderson (2013, p. 313) strong support for the broad conclusion: ‘To date, almost all of the studies that have manipulated disgust or cleanliness have reported effects on moral judgment. These findings strengthen the case for a causal relationship between disgust and moral judgment, by showing that experimentally evoked disgust—or cleanliness, its opposite—can influence moral cognition.’ Note, however, that in later work Chapman (2018, pp. 73–4) revises this view in light of new evidence: ‘a recent meta-analysis of disgust induction studies suggests that incidental disgust has at best a small effect on moral judgment (Landy & Goodwin, 2015).’ ↩︎

  4. This is what I originally concluded, and what I say in the recording (‘overwhelmingly yes’ at 10:42). When I eventually update the recording, I will not say that. ↩︎

  5. Schnall, Haidt, Clore, & Jordan (2015) contest the latters’ conclusions; Landy & Goodwin (2015b) make some interesting concessions in reply. ↩︎

  6. McAuliffe (2019) also provides a review, but this is less nuanced. There are philosophical discussions, offering interestingly different perspectives, in May (2014), May (2018) and Kumar (2016). We will consider Kumar (2016) later in the context of dual process theories. ↩︎

  7. Possible sources include Ugazio et al. (2012). They aim to ‘uncover the mechanisms by which emotions exert their influence on moral judgments’ (p. 587) by comparing the effects of different emotions—anger and disgust—on responses to four scenarios involving moral violations. Further, Decety & Cacioppo (2012) argue that ’moral reasoning involves a complex integration between emotion and cognition that gradually changes with age.’ ↩︎