If There Is Much In The Window There Should Be More In The Room

Monday, June 8, 2009

A 10-Million-Year-Old Laugh -- Morell 2009 (604): 1 -- ScienceNOW


It's something all humans do, regardless of race, culture, language, or creed: laugh.
And, it turns out, some 10 million to 16 million years ago, the last common ancestor of humans and apes was laughing, too, most likely when tickled.

That's the conclusion of an analysis of the recorded laughs of young orangutans, chimpanzees, and human children....


  1. You're welcome, Fred...
    Reactions to tactile touch,
    particularly to that related
    to playing and social relations,
    is essentially the same for
    humans and apes as well.
    Only differs with when and how it sounds:
    we laugh only while exhaling,
    but apes laughed while inhaling too.
    Ours are more "voiced" sounds
    that yield rich harmonics because
    of the vibration of the larynx's
    vocal folds at regular frequencies,
    while theirs are more "noisy" sounds
    like grunts from irregular
    vocal folds vibrations.
    When tickled, there arise
    some involuntary movements
    causing laughs...

    One question though is,
    could the laugh also be a psychological
    reaction more than physiological?
    Some humans particularly sensible
    to tickling frequently start laughing
    even before being really touched,
    as a defense or conditioned reflex
    against more possible physical contacts....