Making a mockery of laughter
Our ape ancestors have used laughter to show they are enjoying themselvesfor 16 million years - but only humans have learned to use laughter to
sneer, mock and ridicule, according to a scientist at the University of
Portsmouth.
Laughter is thought to have been produced in the great ape ancestors of
humans and Asian and African apes.
But while Asian apes just laugh for laughter's sake, African apes learned to
laugh to influence others and humans went one step further and learned to
use laughter for almost every possible social situation, including mockery.
Dr Marina Davila Ross's research is published in the latest issue of
Communicative and Integrative Biology and builds on earlier work published
in 2009 which found that humans learned to laugh from our great ape
ancestors. That work has been nominated by Popular Science magazine as one
of the best research contributions to science for 2009.
She said: 'Humans and the African ape developed laughter further than the
Asian great ape to have an effect on others.
'But something happened in the last five million years which means humans
use laughter for a much wider range of situations than our primate
ancestors. Laughter occurs in close to every imaginable form of human social
interaction, including to mock others.'
Dr Davila Ross is a research fellow in the Department of Psychology. She
said although laughter was present in all descendants of the great apes, the sound of laughter changed throughout evolution. Their new findings indicate
that these changes in sound occurred together with changes in laughing
behaviour of the species.
'Our observations showed strong differences in the use of laughter between
the Asian great apes (orangutans) and the African great apes (gorillas,
chimpanzees, and bonobos). Asian great apes tend to squeak more than laugh,
while African apes and humans laugh clearly more often.
'Based on our findings, we can conclude that 10-16 million years ago
laughter was a sound with limited use. It probably had little effect on the
way others behave.
'Our findings suggest two important periods of selection-driven changes in
laughter of great apes and humans.'
Dr Davila Ross and her colleagues Michael Owren, of Georgia State
University, and Elke Zimmermann, of University of Veterinary Medicine in
Hannover, also showed that sounds other than laughter can evolve in the
context of tickling and play. Other mammals, including flying foxes, make
sounds when they are tickled but they are not necessarily laughing (see
video).
Dr Davila Ross studied the call diversity of wild orangutan populations in
Borneo and Sumatra for her Masters and, for her neuroscience PhD, studied
the evolution of laughter and positive communication of all four great ape
species and humans. She is a member of The Centre for the Study of Emotion
and the Animals Behaviour Research Group at the University of Portsmouth.
