Viki’s ability to imitate was first noticed in her play at an early age. As her skills developed, her human “parents” began to develop exercises specifically geared to gauge her imitation abilities and what effect they had on her learning. They implemented an imitative training program at the age of 17 months.

The clip shows Viki at 25 months imitating Cathy as she pounds a table with a lipstick, then later imitates the action of putting lipstick on her lips. As a reward for her correct imitations, Viki gets a drink of milk. Note that Viki uses her left hand to pound and to pick up the drink, but uses her right for applying lipstick. Chimpanzees are handed, just like humans, but roughly half are left-handed and half are right-handed.