Conversations between speakers with normal hearing and between deaf users of American Sign Language (ASL) are filled with vocal laughter, but the placement of laughter in these vocal and manual conversations is not random. The speaker – the person sending a vocal or signed message – typically laughs before and after complete statements and questions, seldom interrupting phrase structure. Thus, a speaker may say or sign, “I have to go now – ha-ha,” but rarely, “I have to – ha-ha – go now.” The placement of laughter in vocal or signed conversation is akin to punctuation in written text and is termed the punctuation effect (Provine Reference Provine1993; Reference Provine2000; Reference Provine2016; Provine & Emmorey Reference Provine and Emmorey2006). Observations of conversational laughter reveal common features of speaking and signing beyond punctuation. For example, in both hearing speakers (Provine Reference Provine1993) and deaf signers (Provine & Emmorey Reference Provine and Emmorey2006), males are the best laugh-getters (Provine Reference Provine1993), and most laughter does not follow humor (Provine Reference Provine1993). For hearing and deaf people, the essential requirement for laughter is playful social relationships, not jokes or other attempts to stimulate laughter (Provine & Fisher Reference Provine and Fisher1989).

Punctuation has significant neurolinguistic implications. Laughter rarely intrudes on the phrase structure of spoken (Provine Reference Provine1993) or signed conversation (Provine & Emmorey Reference Provine and Emmorey2006), indicating that language, whether vocal or signed, is dominant over laughter. When laughter competes with speech/signing during conversation, language usually wins. Punctuation is also present in the visual domain of text, a nonvocal linguistic medium. Emoticons (visual symbols of emotion such as LOL, “Laughing Out Loud,” etc.) seldom disrupt phrases in online text messages (Provine et al. Reference Provine, Spencer and Mandel2007). Emoticons occur in positions like this . But not like this. Unlike the case of speech and laughter that involves competition for the vocal tract, neither manual signing nor text messaging competes with laughter for a shared organ of expression. The presence of punctuation across this diverse range of expressive behaviors (speaking, signing, texting) indicates that it is the product of a higher-level neurolinguistic mechanism, not a lower-level gate-keeping mechanism that regulates motor acts competing for an organ of expression such as the vocal tract.

Punctuation is not unique to laughter in speech, signing, and texting, indicating the generality of the effect. Airway maneuvers other than speech show punctuation and the priority of linguistic over other forms of expression. Speech involves breath-holding and redirecting the respiratory apparatus to vocalizing. People either speak or breathe during conversation, with breaths coming at linguistically significant punctuation points similar to those described for laughter (McFarland Reference McFarland2001). (It is not known whether breathing punctuates signing.) This complex respiratory, vocal, and linguistic choreography occurs automatically; we do not consciously plan when to breathe, talk, or laugh. Significantly, laughter is under weak voluntary control. When asked to laugh on command, most individuals comment that they cannot do it, or gamely provide unrealistic, fake laughter (Provine Reference Provine2012, pp. 217–20). Laughing is not a matter of deciding to say “ha-ha.” In the proper social context, laughter simply happens.

Goldin-Meadow & Brentari argue for the value of broadly based, comparative analyses of signing, gesturing, and speaking. I consider the benefits of further extending the range of communicative acts to include the utterance of laughter and its associated neurolinguistic phenomena.