Before revision:  The integration of the two basic mechanisms of imitation and attention to novelty allows to understand diverse competing objects, with lifetimes that range from hours for memes and news (7, 8) to decades for verbs . This suggests a general mechanism underlying cultural evolution.
After revision:  The integration of the two basic mechanisms of imitation and attention to novelty allows to understand diverse competing objects, with lifetimes that range from hours for memes and news (7, 8) to decades for verbs , suggesting the existence of a general mechanism underlying cultural evolution.