Um. I'm thinking that the children were being shown how to carry out the activity by a member of their own species, whereas the chimps and orangs were being asked to imitate human beings. Maybe it's easier to imitate your own species than a different one?

I also wonder how old the chimps and orangs were, and whether imitative behaviour may be influenced by age as well as species?

So, on the whole, I'm thinking fascinating but perhaps not quite in the way the news report suggests. Would have been interesting to hear how the Orangs and the chimps were different, too.