Opinion: What makes things humorous.

In a familiar parable, a group of blind men try to discern the shape of an elephant, but each man’s perspective differs depending on whether he’s touching the trunk, tusk, or tail (Fig. 1). After 2,500 years of studying humor, scientists similarly have differing perspectives on what makes things funny (1). We present three common perspectives on humor. Although each is insightful, no one perspective suffices to explain why so many dissimilar things—tickle attacks, foolish behavior, puns, absurdities, and sitcoms—can be humorous. However, integrating the three perspectives into an account of humor as a response to benign violations discerns the whole animal from its parts and thus better explains how laughter and amusement come about. One perspective discusses humor’s negative underpinnings. Accumulating evidence across academic disciplines identifies how humor is typically preceded by a violation, or some kind of threat to a person’s wellbeing, identity, or normative belief structure (2). Ethologists find that friendly physical aggression, such as rough-and-tumble play or tickling, produces laughter in nonhuman animals, and the so-called victim does more of the laughing (3). Anthropologists document how people across cultures participate in joking relationships by teasing and insulting one another using “a peculiar combination of friendliness and antagonism” (4). Even simple verbal statements are more humorous when they are illogical (e.g., “a pig with impeccable table manners”) or aggressive (e.g., “a donkey that kicks below the belt”) than when logical and nonaggressive (e.g., “a cow that eats grass”) (5). The etymology of humor-related words also points to humor’s dark side. The word “funny” can reference something that seems peculiar, and saying that someone possessed humor once meant the person behaved strangely or was mentally troubled (1). A second—ostensibly conflicting—perspective reveals that humor occurs when things seem safe, playful, acceptable, or benign. Psychologists find that frightening, anxiety-provoking, and otherwise negative experiences can evoke humor when the situation is playful (1). For example, people told that they would be extracting blood from a live rat were amused to discover a toy rat (6). Similarly, experimental participants who read a potentially humorous story about a murder plot or a sexual encounter were more likely to find the story amusing when they read it for fun (i.e., when they were in a nonserious state of mind) than when instructed to carefully evaluate its content [i.e., when they were in a serious, goal-oriented state (7)]. Additional evidence comes from physiology studies that show that laughter corresponds with motor inhibition and muscle weakness, changes associated with being in a safe environment (8). Moreover, neuroscientists document how jokes and cartoons activate areas of the brain that are associated with positivity and reward (9). This finding is revealing because positive emotions generally occur only when people feel safe from harm and immune to pressing concerns (10). A third perspective helps reconcile the previous two by associating humor with conflicting, ambiguous, or incongruous interpretations. Linguists propose that script opposition—a text that can be interpreted multiple, opposing ways—is a common characteristic of verbal jokes (11). For example, a baker could interpret the compliment “nice buns” as praise of either his baking ability or his appearance. Neuroscientists affirm that humor perception corresponds with activation in brain areas associated with incongruity detection, including the temporo-occipital junction (9). Humorous videos (e.g., a child catapulted into the air by an inflatable couch) elicit greater temporo-occipital junction activation than either nonhumorous, positive clips (e.g., children breakdancing) or nonhumorous, neutral clips (e.g., children riding bicycles) (12). Even behavioral responses to