It has been proposed that social interdependence fosters holistic cognition, that is, a tendency to attend to the broad perceptual and cognitive field, rather than to a focal object and its properties, and a tendency to reason in terms of relationships and similarities, rather than rules and categories. This hypothesis has been supported mostly by demonstrations showing that East Asians, who are relatively interdependent, reason and perceive in a more holistic fashion than do Westerners. We examined holistic cognitive tendencies in attention, categorization, and reasoning in three types of communities that belong to the same national, geographic, ethnic, and linguistic regions and yet vary in their degree of social interdependence: farming, fishing, and herding communities in Turkey's eastern Black Sea region. As predicted, members of farming and fishing communities, which emphasize harmonious social interdependence, exhibited greater holistic tendencies than members of herding communities, which emphasize individual decision making and foster social independence. Our findings have implications for how ecocultural factors may have lasting consequences on important aspects of cognition.