Facebook’s “in-house sociologist” Cameron Marlow noted that an average man—one with 120 friends—generally responds to the postings of only seven of those friends. This is consistent with Dunbar's number, the theoretical cognitive limit to the number (150) of people with whom one can maintain stable social relationships. "How can social media mavens move beyond the 5-10% that seems to be the human threshold for meaningful interaction?" asks Kari Dunn Saratovsky of Social Citizens.