Philosophers often consider what it is that makes individuals human. For biologists considering the same, the answer is often framed in the context of what are the key differences between humans and other animals. One vestige of human uniqueness still often cited by anthropologists is culture. However, this notion has been challenged in recent years with numerous demonstrations of "culture" in other species, particularly primates. In this review, the author first considers what the term means to animal behaviorists, and theories about how cultural transmission can occur in other species. He then reviews some of the most striking examples of non-human culture. Most of the examples discussed in this article are narrow in focus, concerning a single feature of tool use, food acquisition or consumption, or communication. He then expands the focus, considering cases of non-human "social culture." By this term, the author means where a particular style of sociality permeates an array of behaviors, with this assemblage of traits fulfilling the criteria for culture. The author also examines in some detail a recent study presenting the most detailed case of transmission of a social culture in a non-human species, one involving a group of primates with a multi-generational culture of low rates of aggression and high rates of affiliative behaviors (such as social grooming, play or sitting in contact). Lastly, the author suggests that this "peaceable" non-human primate culture may be relevant to the human condition.