People moralize many curious things: standing quietly for the national anthem, dressing modestly, standing to the right on the escalator, and separating recycling from garbage. While some of these actions have clear utility for society, others seem to have a relatively arbitrary nature with a confusing moral status. Indeed, if asked, people can even moralize whether someone wears a sweater-vest or not (Van Bavel et al. Reference Van Bavel, Packer, Haas and Cunningham2012). The target article by Stanford, with extension, provides a framework to help understand why everyday behaviours and rituals can take on moral significance. In the target article, Stanford proposes that the externalization of moral demands, which shifts experience from one of internal preference to one of obligation, evolved as a way for people to identify potential partners for productive interaction. Observing behaviour in moral situations provides a great deal of information about a person's character and role in the social collective; someone who donates a kidney to a complete stranger (Marsh et al. Reference Marsh, Stoycos, Brethel-Haurwitz, Robinson, VanMeter and Cardinale2014) can likely be trusted in times of crisis, whereas someone who loots the apartments of a burning building has already shown themselves to be untrustworthy in social exchange. Comparing people to moral scripts tells us a lot about not only their preferences, but also their moral dispositions (Uhlmann et al. Reference Uhlmann, Pizarro and Diermeier2015) and the degree to which they have internalized an objective set of society-building rules.

Yet, although behaviour in moral situations is extremely diagnostic, the chances of observing someone make decisions in extreme situations is rare. This presents a challenge – we need to develop models of others that allow for an understanding of their moral character, but we are not often given the experiences that are most diagnostic in forming such representations. To help people make predictions about the moral character of others – predictions that are necessary for productive interaction – we propose that societies develop norms, games, and conventional rituals that allow for moral behaviour to play out in a relatively more symbolic form. By observing symbolic forms of moral behaviour, people can infer the extent to which others understand and are willing to conform to the moral demands imposed by society. On this view, everyday rituals, such as standing for the national anthem or shaking hands at a job interview, transmit the social norms of society (Rossano Reference Rossano2012) and indicate whether others will follow rules (Watanabe & Smuts Reference Watanabe and Smuts1999). Games provide a similar function, allowing individuals across species to learn the standards they will be held to in society (Allen & Bekoff Reference Allen and Bekoff2005; Bekoff Reference Bekoff2001; Rakoczy Reference Rakoczy2007; Rakoczy & Tomasello Reference Rakoczy, Tomasello and Tsohatzidis2007) and to predict whether others are likely to follow these standards. Applying this to the moral domain, these low-stakes games allow people to form impressions and predict how others will act in more serious moral situations. In this way, we can collect social information through games and ordinary rituals, using others’ adherence to such rituals as indicators of potential adherence to moral norms. A prominent example is the ritual of gift exchanges on birthdays: the continued yearly passing of a $20 gift card between two people signals that they continue to value reciprocal exchange. A friend who neglects their end of the exchange signals low trustworthiness and therefore might not be a good choice as a business partner. The unspoken rules within these rituals become moralized in themselves – the friend who disregards conventional gift-giving may be viewed as less invested in the group.

The rituals through which we signal moral character are externally imposed by society, providing an easily observable objective standard to which others can be held. Those who abide by the standards are seen as moral rule-followers, whereas failing to meet these standards results in condemnation of one's character and reduced opportunities for productive cooperation. Although such moral signaling may be costly, it persists because of the tendency to focus on others’ actions rather than words in determining moral character (Henrich Reference Henrich2009). Therefore, despite any potential inconvenience, we dogmatically abide by the rules within these rituals in order to signal to others that we can be trusted.

Although the standards implied by these rituals are externally imposed, the specific behaviours that are moralized will depend on the moral principles that a particular person values. One important distinction is between individual-based moral foundations, centering around harm and fairness, and group-based moral foundations, focusing on authority, in-group loyalty, and purity (Haidt & Joseph Reference Haidt and Joseph2004; Reference Haidt and Joseph2007). The rituals that people use as cues for moral norm-following will likely differ based on the principles they are primarily concerned with – someone who values individual-based moral foundations may judge others who cheat at board games or take the last piece of cake, while someone who values group-based foundations may be more concerned with whether others dress appropriately or stand for the national anthem. In deciding which rituals are most diagnostic of moral behaviour, the social information that is collected can be tailored to each individual's moral concerns.

Critically, this conceptualization provides a framework for understanding why people sometimes moralize everyday behaviours. Because truly exceptional behaviours are rare, we must rely on other ways of forming impressions to adequately predict people's behaviours when extraordinary situations arise. Creating rules by externalizing everyday behaviours, such as dressing in appropriate ways or recycling, allows us to do this. Morality is readily inferred from these everyday behaviours, with people reporting moral or immoral events in almost a third of their reports throughout the day (Hofmann et al. Reference Hofmann, Wisneski, Brandt and Skitka2014). Because these behaviours are common, adherence to the norms governing them may be used as cues for whether people will abide by more serious moral norms. For example, although support for environmental policies is not readily observable, people can easily see whether others make the effort to recycle. Policy support may therefore be inferred from recycling behaviour; failing to abide by this norm then results in moral condemnation. Through this process, even norms that are not inherently moral may become externalized.