Scientists discovered that orangutan's laughter is infectious (to other orangutans, that is). And that evolutionarily, this may be a precursor to human emotions:
Orang-utans can also make each other chuckle – in fact, they are now thought to have developed laughter before us.
Our close biological cousins have a sense of empathy and mimicry which is an essential part of laughter, scientists at Portsmouth University discovered.
When one orang-utan displayed an open, gaping mouth – the equivalent of laughter – its playmate displayed the same expression less than half a second later, suggesting the mimicry was an involuntary display, their research showed.
they are NOW thought to have developed laughter before us? didn't they EXIST before us?
One thought is that Orangutans exist before human, but humans developed laughter whereas orangutans never did. But this research proved it wrong: orangutans have been laughing before humans evolved.
Just proves that we're really cousins..hehe :))