Link Search Menu Expand Document

Why Is the Affect Heuristic Significant?

Why does it matter whether or not we use the Affect Heuristic? According to its defenders, it has implications for the foundations of ethics.

This recording is also available on stream (no ads; search enabled). Or you can view just the slides (no audio or video). You should not watch the recording this year, it’s all happening live (advice).

If the video isn’t working you could also watch it on youtube. Or you can view just the slides (no audio or video). You should not watch the recording this year, it’s all happening live (advice).

If the slides are not working, or you prefer them full screen, please try this link.

The recording is available on stream and youtube.


Two Implications of the Affect Heuristic for Ethics

First implication: ‘if moral intuitions result from heuristics, [... philosophers] must stop claiming direct insight into moral properties’ (Sinnott-Armstrong, Young, & Cushman, 2010, p. 268).[1]

Second implication: ‘Just as non-moral heuristics lack reliability in unusual situations, so do moral intuitions’ (Sinnott-Armstrong et al., 2010, p. 268).

The second implication is relevant to evaluating objections to consequentialism:

‘Critics often argue that consequentialism can’t be accurate, because it implies moral judgments that are counter-intuitive, such as that we are morally permitted to punish an innocent person in the well-known example where this is necessary to stop riots and prevent deaths. With the heuristic model in hand, consequentialists can respond that the target attribute is having the best consequences, and any intuitions to the contrary result from substituting a heuristic attribute’ (Sinnott-Armstrong et al., 2010, p. 269).

Wilson (who does not explicitly endorse the hypothesis that moral intuitions are a consequence of reliance on the Affect Hypothesis) makes an even stronger claim:

‘ethical philosophers intuit the deontological canons of morality by consulting the emotive centers of their own hypothalamic-limbic system ... Only by interpreting the activity of the emotive centers as a biological adaptation can the meaning of the canons be deciphered’ (Wilson, 1975, p. 563 quoted in Haidt, 2008, p. 68).

If this is right, you cannot understand ethics at all without knowledge of emotional processes. Wilson links this claim to a strong form of ethical pluralism:

‘a schedule of sex- and age-depend­ent ethics can impart higher genetic fitness than a single moral code which is applied uniformly to all sex-age groups. [...] no single set of moral standards can be applied to all human populations, let alone all sex-age classes within each population. To impose a uniform code is therefore to create complex, intractable moral dilemmas—these, of course, are the cur­rent condition of mankind’ (Wilson, 1975, pp. 563--4).

But should we accept any of these claims? Are they supported by evidence (or argument)?

Background: Understanding Heuristics

To gain a better understanding of heuristics, it may be helpful to consider a nonmoral case where we have good evidence that heuristics matter.

Pachur, Hertwig, & Steinmann (2012) investigated how naive humans’ answer track three questions:

  • frequency—Which cause of death has a higher annual mortality rate?
  • risk—Which cause of death represents a higher risk of dying from it?[2]
  • Value of a Statistical Life (VSL)—How much money should be spent to avoid one fatality due to this cause of death?[3]

You can see the actual frequencies (in Switzerland) and the subjects’ median estimates of frequency for various causes of death in Table 2 of Pachur et al. (2012).

What did the subjects compute that enabled them to answer questions about frequency, risk and the value of a statistical life? Since these attributes tracked were inaccessible to the subjects, they cannot have been computing the attributues themselves. Instead they must have been computing something which, within limits, correlates with the attributes (like tracking toxicity by computing how smelling or tasting a potential food makes you feel; see Moral Intuitions and an Affect Heuristic).

In this situation, there are at least two heuristics the subjects might use:

Availability Heuristic The easier it is to bring a case of this cancer to mind, the more frequent or risky it is.

Affect Heuristic (for frequency and risk[4]) The more dread you feel when imagining it, the more frequent or risky it is.

Pachur et al. (2012) propose a hypothesis about how different attributes are tracked using different heuristics:

Hypothesis: The Availability Heuristic dominates frequency judgements, whereas the Affect Heuristic dominates risk and VSL judgements.

This hypothesis generates a readily testable prediction:

Prediction: Number of cases in a subject’s social network will better predict frequency judgements, whereas feelings of dread will better predict risk and VSL judgements.

Pachur et al. (2012) tested these predictions. They found that:

‘availability-by-recall offered a substantially better descriptive account than the affect heuristic when people judged deindividualized, statistical mortality rates. Affect, however, was at least on par with availability when people were asked to put a price tag on a single life saved from a risk, or when they were asked to indicate the perceived risk of dying’ (p. 324).

These findings provide a paradigm case where a hypothesis about a heuristic was successfully established.

Ask a Question

Your question will normally be answered in the question session of the next lecture.

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 et al., 2012, which is discussed in The Affect Heuristic and Risk: A Case Study).
heuristic : A heuristic links an inaccessible attribute to an accessible attribute such that, within a limited but useful range of situations, someone could track the inaccessible attribute by computing the accessible attribute.
inaccessible : An attribute is inaccessible in a context just if it is difficult or impossible, in that context, to discern substantive truths about that attribute. For example, in ordinary life and for most people the attribute being further from Kilmery (in Wales) than Steve’s brother Matt is would be inaccessible.
See Kahneman & Frederick (2005, p. 271): ‘We adopt the term accessibility to refer to the ease (or effort) with which particular mental contents come to mind.’
tracking an attribute : For a process to track an attribute is for the presence or absence of the attribute to make a difference to how the process unfolds, where this is not an accident. (And for a system or device to track an attribute is for some process in that system or device to track it.)
Tracking an attribute is contrasted with computing it. Unlike tracking, computing typically requires that the attribute be represented. (The distinction between tracking and computing is a topic of Moral Intuitions and an Affect Heuristic.)
unfamiliar problem : An unfamiliar problem (or situation) is one ‘with which we have inadequate evolutionary, cultural, or personal experience’ (Greene, 2014, p. 714).


Audi, R. (2019). Understanding, Self-Evidence, and Justification. Philosophy and Phenomenological Research, 99(2), 358–381.
Greene, J. D. (2014). Beyond Point-and-Shoot Morality: Why Cognitive (Neuro)Science Matters for Ethics. Ethics, 124(4), 695–726.
Haidt, J. (2008). Morality. Perspectives on Psychological Science, 3(1), 65–72.
Kahneman, D., & Frederick, S. (2005). A model of heuristic judgment. In K. J. Holyoak & R. G. Morrison (Eds.), The cambridge handbook of thinking and reasoning (pp. 267–293). Cambridge: Cambridge University Press.
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.
Raichle, M. E., & Gusnard, D. A. (2002). Appraising the brain’s energy budget. Proceedings of the National Academy of Sciences, 99(16), 10237–10239.
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.
Stratton-Lake, P. (Ed.). (2002). Ethical intuitionism: Re-evaluations. Oxford: Clarendon Press.
Tybur, J. M., Lieberman, D., & Griskevicius, V. (2009). Microbes, mating, and morality: Individual differences in three functional domains of disgust. Journal of Personality and Social Psychology, 97(1), 103–122.
Vanaman, M. E., & Chapman, H. A. (2020). Disgust and disgust-driven moral concerns predict support for restrictions on transgender bathroom access. Politics and the Life Sciences, 39(2), 200–214.
Wagemans, F. M., Brandt, M., & Zeelenberg, M. (2018). Disgust Sensitivity Is Primarily Associated With Purity-Based Moral Judgments. Emotion, 18(2), 277–289.
Wilson, E. O. (1975). Sociobiology: The new synthesis. Cambridge, Mass: Belknap Press of Harvard University Press.


  1. I am doubtful that this really is an implication: if I understand Sinnott-Armstrong et al. (2010)’s position, there would be no need for heuristics at all if moral attributes were not inaccessible—so it appears to me as if the inaccessibility of moral attributes is a premise rather than an implication. Note also that these philosophers’ claim is quite narrow and does not bear directly on the view that ethical propositions may be self-evident if self-evidence is understood along the lines of Audi (2019). (Thanks to Paul Theo here.) ↩︎

  2. You might reasonably hold that frequency and risk in this sense are not distinct, which is what Pachur et al. (2012) intend. But you will see that people tend to make different judgements in response to the risk and frequency questions. ↩︎

  3. The lecture omits discussion of VSL for simplicity. ↩︎

  4. Yes, it is potentially confusing that we are using the same term, ‘Affect Heuristic’ for a different heuristic. The common theme is tracking an attribute by computing how something makes you feel. ↩︎