one of the other great scientist from the Max Planck Institute is Michael Tomasello http://email.eva.mpg.de/~tomas/ (he works with Chimpanzee too and make the same experiments with human children to explore what is specific about humans). Many interesting of his lectures/interview vid online.
It's an example of intuition. Also some birds display intuition-like behavior, so this cognitive feature probably goes back a long way. Being able to intuit a solution means imagining a solution (a sort of internal simulation) then formulating a plan and then carrying out the plan. Intuitive behavior doesn't require large numbers of trial and error efforts, as you would see with less intelligent creatures.
