My previous understanding was that chimps imitate, but don't teach: http://www.pbs.org/wgbh/nova/nature/ape-genius.html http://www.pbs.org/wgbh/nova/nature/ape-

My previous understanding was that chimps imitate, but don't teach: http://www.pbs.org/wgbh/nova/nature/ape-genius.html http://www.pbs.org/wgbh/nova/nature/ape-genius.html The article you linked said the chimps were teaching, but was rather vague about how. It seemed to be more focused on the nut cracking behavior, so it's hard to tell if they are actually teaching or just learning by example. As with most other traits, it may be that it's not that other animals don't teach. Instead maybe it's matter of degrees: chimps don't teach much, humans teach a lot. The lack of altruism might explain why chimps mostly don't bother to teach other chimps, even though they have the ability.