Evolution, Structure, and Functions of Human Laughter

• Published in: The Handbook of Communication Science and Biology pp. 63 - 77
• Main Author: Bryant, Gregory A.
• Format: Book Chapter
• Language: English
• Published: Routledge 2020
• Edition: 1
• Subjects: Voiceless Glottal Fricatives; Frontoparietal Attention Network; Adaptive Communication System; Supplementary Motor Area; Vocal Emotion; Nonhuman Animals; Play Vocalizations; Shared Laughter; Vice Versa; Human Laughter; AET; Social Communicative Functions; Fundamental Frequency; Intercostal Muscles; Vocal Folds; Conversational Turn Taking; Stimulus Clips; Affection Exchange Theory; MIDUS Study; Task Positive Network; Sexual Concordance; Bilateral Temporoparietal Junction
• ISBN: 0815376731; 9780815376736; 9780815376712; 0815376715
• DOI: 10.4324/9781351235587-7

Human laughter constitutes a family of nonverbal social vocalizations phylogenetically related to play vocalizations in nonhuman animals. The evolution of articulated speech introduced a second pathway for vocal signaling, including volitional laughter, that afforded multiple interactive functions manifesting in conversational turn-taking and group contexts. Most social functions of laughing relate to coalitional social strategies, including the development of extended social ties for successful long-term cooperative relationships. Laughter provides a unique window into human vocal signaling and cooperative behavior, as well as an example of how ancestral communicative behaviors become integrated with later evolving systems. This chapter discusses the human laughter from an evolutionary perspective, including discussion of its basic acoustic structure, phylogenetic origins, and social communicative functions. Human laughter constitutes a family of nonverbal social vocalizations phylogenetically related to play vocalizations in nonhuman animals. The evolution of articulated speech introduced a pathway for vocal signaling, including volitional laughter, that afforded multiple interactive functions manifesting in conversational turn-taking and group contexts. In the case of play vocalizations, the heavy breathing associated with excessive play provides honest information about the physical state of the participants and reveals vulnerability. The continued play indicates a willingness to be vulnerable, trust in the social partner, and an investment in the action itself. An additional factor in humans that dramatically complicates the theoretical picture for laughter is the evolution of the speech capacity that works in conjunction with vocal emotions.