Tatone, DenisCsibra, Gergely2022-03-2920150140-525Xhttp://dx.doi.org/10.1017/s0140525x14000740http://hdl.handle.net/20.500.14018/11699We argue that direct active teaching in humans exhibits at least two properties (open-endedness and content opacity) that make the recognition of teaching episodes without ostension untenable. Thus, while we welcome Kline’s functional approach to the analysis of teaching, we think that she ignores important features of the socio- environmental niche in which human teaching likely evolved.engLearning in and about opaque worlds. Commentary on: How to learn about teaching. An evolutionary framework for the study of teaching behavior in humans and other animals, by Michelle Ann KlineJournal article