The Principle of Sufficient Reason (PSR) has been an influential thesis since the earliest stages of western philosophy. According to a simple version of the PSR, for every fact, there must be an explanation of that fact. In the present research, we investigate whether people presuppose a PSR-like principle in judgment. Across four studies (N = 1,007 in total, U.S., Prolific), we find that participants consistently presuppose PSR in judgments about candidate explananda. Such judgments predictably track the metaphysical aspects relevant to the PSR (Study 1) and diverge from related epistemic judgments (Study 2) and value judgments (Study 3). Moreover, we find participants’ PSR-affirming judgments apply to a large set of facts that were sampled from random Wikipedia entries (Studies 4). These findings suggest that certain metaphysical judgments play an important role in our explanatory activities, one that is distinct from the role of the epistemic and value judgments that have been the focus of much recent work in cognitive psychology and philosophy of science.

A good deal of recent research has examined children’s norm learning across a wide range of novel contexts. The typical interpretation of these findings is that children’s norm learning is driven by group-based biases. In this paper, we present an alternative interpretation and corresponding meta-analyses that cast the current body of evidence in a rather different light. First, we argue the extant literature uses an ill-suited standard for assessing bias. Rather than comparing children’s judgments to what is expected under random chance (a ‘random standard’), bias is better assessed by comparing children’s judgments to what is most probable, given their total evidence (an ‘evidential standard’). Next, we report a meta-analysis of the known findings to date (k = 40 effect sizes; N = 1,369 in total; ages 4- to 13-years-old) to compare children’s norm learning against an appropriate evidential standard. Meta-analytic estimates reveal that children’s norm learning is not restrictively biased toward narrow-scope inferences on account of group-based factors. Rather, the findings to date are consistent with children’s norm learning being rational (i.e., statistically appropriate, given their evidence) or even inclusively biased toward making the wide-scope inference that a novel norm applies to everyone in a population. We conclude with brief discussion of implications for current understanding and future research on norm acquisition.

It’s a familiar point in anthropology that many norms are parochial, meaning they apply to people in certain groups (e.g., one’s ingroup) and not to others (e.g., one’s outgroup). One explanation for such parochialism is that people are just innately biased against outsiders. But it’s also possible that, given the evidence, people infer the parochiality of norms in statistically appropriate ways. This paper uses a Bayesian learning framework to investigate inferences of normative scope both experimentally and computationally. An experiment in which adult participants (n = 480) viewed sample violations of a novel rule among novel groups reveals that both sensitivity to statistical evidence and prior knowledge of relevant social categories are integral to computations of normative scope. In tandem with the experimental results, computational analysis supports the notion that degree of prior inclusivity bias (i.e., an expectation that a norm will be broad, rather than narrow, in scope) is another key factor. Together, these novel insights raise intriguing possibilities for integrating perspectives on norms research.