The triple theory of moral cognition (Levine et al.,) posits that people judge the morality of interdependent choices by assessing whether they reflect “mutually beneficial agreements” between affected parties, using cognitively efficient (but reasonably accurate) shortcuts whenever necessary. Yet some of society’s most contentious moral disagreements involve cases where the affected parties have established such agreements and are nonetheless judged as immoral by some third-party observers. Consider decisions like same-sex relationships, physician-assisted dying, and sex work. The most cognitively efficient and accurate route to making a moral judgment, under contractualism, would be for observers to simply accept others’ apparently consensual decisions as mutually beneficial and therefore moral, yet this clearly does not always occur. We can think of two ways to explain these apparent failures to optimize efficiency and accuracy within the contractualist framework, but both call for some additions to the triple theory.

The first possibility is that observers engage in their own cost-benefit analysis of the situation to evaluate whether an arrangement is mutually beneficial and therefore moral (see Gray, Schein, & Ward, Reference Gray, Schein and Ward2014). However, what counts as “beneficial” is subjective. Although some costs and benefits of an interaction may be clearly quantifiable (e.g., monetary transactions), there are almost always less tangible goods at stake, such as power, pleasure, and dignity. To one person, sex work could seem like a straightforwardly mutually beneficial exchange, while another might see it as a loss of dignity and virtue, resulting in a net cost to both parties.

Observers might make this subjective valuation from their own perspective; for example, a heterosexual person might judge a same-sex marriage to be immoral if they themselves would not thrive under such an arrangement. They might also attempt to take the perspective of the affected parties in making their subjective valuation (similar to virtual bargaining) but remain ego-centrically anchored in their own point of view (e.g., Birch & Bloom, Reference Birch and Bloom2007; Epley et al., Reference Epley, Keysar, Van Boven and Gilovich2004a; Surtees & Apperly, Reference Surtees and Apperly2012). For example, a heterosexual person might judge a same-sex marriage to be immoral if they struggle to imagine how a queer individual would experience it. Together, these ideas offer an empirical prediction: observers should be especially likely to judge an apparently consensual action as immoral when a) they would subjectively not experience one or both sides of the bargain as beneficial, and b) they struggle with perspective-taking.

If observers make moral judgments about others’ exchanges by computing their own cost-benefit calculation, the challenge for the triple theory would be to explain why they do so even when they could better maximize both cognitive efficiency and accuracy by simply accepting others’ apparent agreements at face value. Making one’s own (ego-centric) valuation can be automatic and therefore need not entail a large cognitive cost (Bocian, Baryla, & Wojciszke, Reference Bocian, Baryla and Wojciszke2020; Epley, Morewedge, & Keysar, Reference Epley, Morewedge and Keysar2004b), but it still poses the risk of inaccurately judging as immoral an arrangement that reflects a genuinely mutually beneficial agreement. One way to justify this risk could be to invoke a countervailing accuracy risk: Doing their own valuations may help observers identify ostensibly consensual agreements that are not actually mutually beneficial (e.g., agreements obtained under coercion).

A second possibility is that moral norms can override ad hoc agreements. Levine and colleagues describe norms as “cached standards,” serving as cognitively efficient heuristics for people’s typical agreements and ensuring an accurate judgment most of the time. By this logic, for example, societies with fewer queer people should develop stronger norms against same-sex relations, as these norms would be more accurate than in societies with more queer people. Moral opposition to same-sex relationships could occur if observers defer to these norms, even in the presence of an apparently consensual same-sex relationship. If so, this offers an alternative prediction: Even if we examine queer observers’ judgments of same-sex relationships, these should be more negative in a society with a smaller queer population and stronger heterosexual norms.

The idea that observers make moral judgments by referring to norms, even when they could instead accept others’ consensual agreements, poses a similar challenge to the theory: It would be at least as efficient, and even more accurate, for an observer to accept others’ agreements at face value. Why consult the norm in the presence of an explicit agreement, even when stakes are uniquely high?

Perhaps accepting any kind of exception to the norm threatens its key characteristic of being generalizable and efficient in the long term. To illustrate, if a doctor and patient agree that physician-assisted dying is the best option for a particular prognosis, accepting this ad hoc agreement would entail accepting exceptions to the norm of “not causing death.” What is right or wrong would then become less clear moving forward (i.e., in what cases you can, permissibly, cause death; for example, see Cecco, Reference Cecco2024), making moral judgment more effortful in the long term.

To preserve the resource rationality of norms, observers may be motivated to align their moral judgments with norms even when a contradictory ad hoc agreement has been struck. They may therefore exert some cognitive effort to discount the agreement and avoid the cost of revising the norm. For instance, they might find ways to deem the affected agents to be irrational or the agreement to be coerced, making it invalid evidence of mutual benefit. Indeed, opponents have argued that queer people are mentally ill and therefore potentially incapable of proper consent (e.g., Bayer, Reference Bayer1987) and that sex work is inherently coercive due to the workers’ financial need (dmkicksballs13, 2022).

People make moral judgments about others’ choices every day. We suggest two possible processes to account for instances when these diverge from others’ actual agreements. We further speculate about how these processes could be resource rational, per the tenets of the triple theory. Whether through these processes or otherwise, we urge Levine et al. to consider how observers’ moral judgments may fit within their framework, as well as how the theory could explain moral disagreements about consent-related issues in our society today.