Scaling up: Material culture as scaffold for the social brain

Many other species besides Homo sapiens are tool-users and even tool-makers, but one aspect of material culture still sets modern humans apart: our emotional and social engagement with objects. Here I argue that this engagement acted as a crucial scaffold for the scaling-up of human social networks beyond those of our closest relatives the chimpanzees to the global 'small world' of modern humans. Material culture plays a vital role in conveying social information about relationships between people, places and things that extend geographically and temporally beyond the here and now - a role which allowed our ancestors to off-load some of the cognitive demands of maintaining such extensive social networks, and thereby surpass the limits to sociality imposed by neurology alone. Broad-scale developments in the archaeological record of the Lower Palaeolithic through to the early Neolithic are used to trace the process by which hominins and humans slowly scaled up their social worlds.