Analogies map novel concepts onto familiar concepts, aiding the learning and transmission of novel information. Analogies have been studied in cognitive science for years; here we connect this literature with the theory of cultural evolution. Cultural evolution provides a framework for understanding how human culture changes over time, but has been criticised for a lack of emphasis on the cognitive and communicative mechanisms that support cultural transmission. We suggest that a simple protolanguage consisting of labels would have catalysed cumulative cultural evolution by allowing analogy-building to proliferate. Labelling a novel object or action in relation to a familiar one would be particularly helpful for the transmission of cognitively opaque sequences, on which much of human cumulative culture relies.