This paper argues that an exploration of colloids can help us situate human social life within a wider understanding of the sociality and animacy of matter. Colloids are substances such as sols, foams, powders, gels, doughs and pastes that exhibit complex and shifting macroscale physical properties that do not conform to standard conceptions of solids, liquids or gases. Colloids can behave in complex and creative ways because of their topological enfolding of dispersed and continuous matter, in different phases, at a ‘mesoscale’ intermediate between the scale of molecules and that of the macroscale substance. I relate colloids, with their twin phenomena of ‘repetition’ and ‘mediation’, to an understanding of social life as reducible neither to the interaction between separate individuals nor to a transindividual whole. I suggest that human social life participates in a colloidal ‘metapattern’ of repetition and mediation that is manifest across diverse material substrates and spatial scales.