Our measure of cumulative cultural change is very general and does not necessarily imply (i) the generation of behavioral complexity via the invention of novel behavioral combinations, or levels technological of complexity, nor (ii) open-ended change [4, 13, 33, 34]. In our model, the latter cannot arise because novel behavioural opportunities cannot be generated, and the cumulative cultural process is restricted to the opportunities that are available in the environment, and is ‘bounded’. Thus, the complexity of behavior remains limited in the sense that any single behavior could be invented within the lifetime of an individual . However, this behavior-level view contrasts with our repertoire-level perspective, where we consider culture cumulative if foragers exhibit a repertoire quality and overall skill level that they could not achieve within a lifetime of asocial learning. Thus while each single behavior could in principle be discovered by any forager, the level of repertoire optimization, or total ‘ecological knowledge’, cannot. In future, this ‘ecological knowledge’ perspective could be extended to spatial knowledge, in order to establish a more complete perspective on the scope of cumulative culture next to diet learning  and skill learning (present study) in group foragers.