The article explores the nature of sociality and alterity in indigenous Amazonia. If native Amazonian sociality is all about predatory affinity or, alternatively, convivial consanguinity, why do native Amazonians constantly strive to establish social relationships with people with whom they are related neither as kin nor as affines? The comparative analysis of intertribal trading partnerships, shamanic networks, and mystical associations allows the author to examine the mechanisms by which hostile or potentially hostile relations between strangers – non-relatives – are transformed into relations of amicability. Special emphasis is placed on the role played by ‘trust’ and ‘spaces of trust’ in the creation of non-kin-based social networks. In brief the article analyses the little-studied issue of ‘friendship’, viewing it as an alternative to kinship and affinity in the construction of Amerindian societies and multi-ethnic polities.