The video off to the left shows what appears to be a very ordinary scene of a chimpanzee putting a peg into a hole, then sliding the toy around on the table. If the video clip were of a human infant, it would hardly seem worthy of note. Apparently the only unusual element of the scene is that Viki is a chimpanzee.

But watch carefully and you will see something special here. Pay particular attention to how Viki successfully maneuvers the peg into the hole. She twists the peg slightly so that the edge of the peg touches the block, then moves the peg around until the edge of the peg drops into the hole. Viki then rotates the peg upright and successfully inserts the peg into the hole.

This is known as a compliant mating of the peg and the hole. It is actually a very sophisticated strategy, but one that Viki clearly appreciates. Viki is also demonstrating sophisticated mechanical abilities far in advance of human babies at the same age (8 months). Chimpanzees mature physically at a much faster rate than humans.