Evolution of laughing

…and speech? or at least "vocal control"?

Chiara De Gregorio, Marina Davila-Ross, & Adriano R. Lameira, "Rhythm and timing in laughter reveal that human vocal plasticity falls on a hominid continuum", Nature Communications Biology, 6/25/2026:

Laughter is an important, universal form of human non-linguistic vocal expression and, being shared by all extant great apes, offers a valuable proxy for tracing the evolution of vocal control that ultimately enabled language. Yet surprisingly little is known about the evolution of its defining feature, rhythm. Here we show, through comparative analyses of laughter across all extant great apes (orangutans, gorillas, bonobos, chimpanzees, humans), that the laughter of the last common ancestor was already isochronous, becoming faster, more variable, and increasingly context-sensitive over hominid evolution. The evolution of laughter’s rhythm reveals a progressive increase in vocal rhythmic plasticity, with humans following the overall trajectory toward enhanced vocal control.

I'm inspired to repeat these semi-serious exhortations from past posts:

"Group glee", 11/30/2006:

If I was the Emperor of Academia, we'd have Departments of Group Glee Studies, Institutes for Interdisciplinary Group Glee Research, international workshops on Cross-cultural Group Glee Investigations, annual meetings of the American Group Glee Association (and its splinter group, the Association for Group Glee Science).

"Autistic dogs: teaching instinctual communication?", 10/29/2009:

I'm adding "sharing of the play mood" to the list of inadequately investigated phenomena headed by "group glee"… Why, amid all the thousands of flowers in the gardens of academia, are there no departments of Play Mood Studies?

In support of future research, if not the founding of departments, centers, and institutes, De Gregorio et al. supply all the data and code used in their study at https://doi.org/10.5281/zenodo.19005404.