Explanations are crucial to our cognitive lives because they inform our understanding of the world, structure our concepts, and guide our actions. Yet, the processes that underlie explanation remain largely unknown: How do people generate, evaluate, and use explanations?

Answering this question is a major challenge, since even a rough specification of the processes involved requires considering a wide range of issues in human cognition: It requires that we understand how explanatory processes access relevant facts in memory; how these processes extract explanation-relevant facts from the evidence in the environment; how implicit computations relevant to generating explanations interact with explicit, working-memory-dependent processes; and so on. In other words, considering explanation as a process forces us to acknowledge and explore the multifaceted nature of this fundamental cognitive ability.

The special issue of Psychonomic Bulletin & Review, guest edited by me and Frank Keil, that stimulated this digital event begins to tackle these complexities. The articles in it provide new, often surprising, insights into the processes involved in generating, evaluating, and using explanations. As a result, this collection of papers is a state-of-the-art tool for any scholar interested in understanding or studying explanation. To orient readers to the content of the special issue, and to open up this digital event, we provide a brief overview of the themes that emerged from the articles.

Several articles investigate the processes involved in generating explanations and illustrate how much our ability to generate explanations depends on other basic cognitive competencies. Hoyos and Gentner, for example, examine how the process of comparing across—and analogizing from—previous experiences is involved in generating explanations. This theme is echoed by the work of Thibodeau, Crow, and Flusberg, who demonstrate the power of explanations that illuminate one phenomenon by drawing an analogy with another. The centrality of comparison to explanation is also highlighted by Chin-Parker and Bradner’s treatment of the ways in which generating explanations involves comparing the actual state of the world (e.g., cutting onions makes us cry) with similar, yet counterfactual, states (e.g., cutting tomatoes doesn’t).

Three papers provide insight into the reciprocal relationship between explanation generation and memory retrieval. Using eye-tracking data, Scholz, Krems, and Jahn are able to reconstruct how memory retrieval shapes the course of explanation generation on a moment-by-moment basis. Rindal, Chrobak, Zaragoza, and Weihing and Soares and Storm examine the other side of the coin—the effect of generating explanations on subsequent memory for the phenomena being explained. The experiments of Rindal and colleagues suggest, for example, that people’s spontaneous tendency to use new information to make sense of previously experienced events “rewrites” these events in memory and may thus lead to unreliable eyewitness testimony.

A second major focus of the special issue is on the processes that shape how people evaluate explanations. For instance, Vasilyeva, Wilkenfeld, and Lombrozo demonstrate that explanations are evaluated in part based on their usefulness to the reasoner: Explanations that support ongoing activities are judged to be better. Bechlivanidis, Lagnado, Zemla, and Sloman investigate the role that the abstraction (versus concreteness) of an explanation plays in its evaluation, finding that concrete explanations are often preferred, as long as they manage to clearly communicate the key properties that caused the explanandum to occur. Mills, Danovitch, Rowles, and Campbell examine the development of children’s ability to evaluate explanations, with a particular focus on the ability to detect empty, circular explanations. Prasada provides a compelling account of the circumstances under which people judge formal explanations (that is, explanations that attribute an individual’s features and behavior to the kind to which it belongs) to be appropriate. Finally, Zemla, Sloman, Bechlivanidis, and Lagnado use a corpus of everyday explanations to examine whether a whole host of previously-hypothesized explanatory “virtues” (simplicity, coherence, etc.) actually predict how people evaluate explanations. One of the more surprising claims of their work is that people often prefer complex explanations that invoke multiple causal mechanisms over simpler explanations.

A third key theme of the special issue explores the downstream consequences of explaining. For instance, explanations are an essential element of learning, and Rittle-Johnson and Loehr provide a timely review of the usefulness (and limits) of eliciting explanations as a learning tool in the classroom. The experiments reported by Baillargeon and DeJong suggest that even infants use explanatory inferences to guide their learning about the physical world. The aforementioned work by Mills and colleagues also highlights how children’s explanations guide their learning: The more sensitive children were to the emptiness of an explanation, the more curious they remained about the phenomenon in question. We see a downstream effect of children’s explanations in the studies by Walker, Bonawitz, and Lombrozo as well. They show that the process of generating explanations leads children to use the “virtues” of explanations (simplicity, in particular) as a guide in their subsequent causal predictions. Legare, Sobel, and Callanan make the case that the link between explanation and learning is best understood by taking into account the sociocultural context. In childhood and beyond, explanations—and the learning they facilitate—are a collaborative process shaped by the cultural norms of one’s community. Although we have so far focused on the link between explanations and learning, the consequences of generating and adopting explanations are much broader. Notably, Weisman and Markman argue for explanation as a tool for health interventions. Clear explanations revealing the causal link between a behavior and a health outcome can be effective means of inducing behavior change.

Finally, the papers in this special issue highlight the ubiquity—indeed, inescapability—of explanations in our mental lives. For example, Gantman, Adriaanse, Gollwitzer, and Oettingen review research suggesting that people are so driven to explain that they explain (or rather confabulate about) the unexplainable: behaviors activated nonconsciously, which are completely inaccessible to introspection. Similarly, Shtulman and Morgan show that people unwittingly apply the causal-explanatory frameworks they use in everyday life to phenomena that fall outside their scope (e.g., impossible events such as levitating objects). The same overconfidence in the power of explanation is documented by Woolley and Cornelius, who also provide a detailed analysis of the development of explanations for mundane, improbable, and extraordinary events.

With its diversity of perspectives and approaches, this special issue makes a unique contribution to the psychology of explanation. Research in this issue should inspire curiosity among a broad spectrum of scientists and spark a new wave of research on this foundational, but still underexplored, cognitive ability.

This digital event that runs for the remainder of this week should help spark a conversation about how the field should move forward.