Socially transmitted behavior in nonhuman primates. A behavior is most likely to be cultural if it is not displayed by every individual in all environments, i.e. if it is customary or habitual in many groups, and absent in others. Criteria suggested by Krober in 1928 for cultural acts in nonhuman species include: innovation, dissemination, standardization, durability, diffusion, and tradition; nonsubsistence and naturalness are additional criteria sometimes appended to Krober’s list. Recent intraspecific studies have nominated 24-39 qualifying behavioral traits in pongids.