A distinctive aspect of human behaviour is the ability to think symbolically. However, tracking the origin of this capability is controversial. From a Peircean perspective, to know if something truly is a symbol we need to know the cultural context in which it was created. Rather than initially asking if materials are symbols/symbolic, we offer that it is more salient to ask how they functioned as signs. Specifically we argue that using the Peircean distinction between qualisigns, sinsigns and legisigns provides support for this endeavour. The ‘flickering’ of early symbolic behaviour (the sporadic occurrences of objects with embedded social meanings in the Pleistocene archaeological record) can best be seen as sinsigns, whereas sites that show long-term presence of such materials are demonstrating the presence of legisigns: the codification of ideas. To illustrate this approach, we apply these ideas to three classes of artefacts, demonstrating how this system can address issues of relevance to palaeoanthropologists and archaeologists who often fetishize the symbolic as the one ability that makes us human.