How deep do we dig? Formal explanations as placeholders for inherent explanations

Formal explanations (e.g., “Mittens has whiskers because she's a cat”) pose an intriguing puzzle in human cognition: they seem like little more than tautologies, yet they are surprisingly commonplace and natural-sounding. To resolve this puzzle, we hypothesized that formal explanations constitute an implicit appeal to a category's inherent features rather than simply to the category itself (as their explicit content would suggest); the latter is just a placeholder. We conducted a series of eight experiments with 951 participants that supported four predictions that followed from this hypothesis: First, formal explanations—though natural-sounding—were not particularly satisfying. Second, for natural kinds, formal explanations were less satisfying than inherent explanations (specifically, ones that appealed to a natural kind's causally powerful “essence”). Third, participants viewed essence-related inherent explanations as more specific versions of the ideas expressed by formal explanations, which were viewed as more general placeholders. Fourth, and finally, formal explanations tended to serve as placeholders for explanations that appealed to inherent features more so than for other types of explanations, such as ones that appealed to external, environmental factors. In addition to supporting our novel claim about the meaning of formal explanations, these data suggest a new way in which explanations do their psychological work: not via their literal content (as assumed by prior work on explanation), but rather via the additional inferences they encourage. We end by discussing the potential heuristic value of formal explanations for causal learning in childhood.