Overview
- A peer-reviewed analysis published June 25, 2026 compared 140 laughter bouts from 17 individuals across all five living great-ape lineages and found regularly timed, or isochronous, bursts in every species sampled.
- Humans produced faster and more variable laughter than other apes and were the only group in the study to change laugh tempo by context, laughing faster when tickled than during free play.
- The regular timing depended on behavior: tickle-induced laughter was highly isochronous while play laughter showed more temporal variation across species.
- The dataset relied mainly on archival ex situ recordings made in 2004–2006 plus a few human children, so small sample sizes and captive settings limit species-level claims and the authors call for larger, wild and more diverse samples.
- The team interprets the shared rhythm as likely present in the last common great-ape ancestor about 15 million years ago and says this conserved timing offers a testable window into the vocal-respiratory changes that may have paved the way for speech.