Rendell and Whitehead have drawn attention to some striking cetacean behaviour patterns. However, the claims for are premature. Weak examples of cetacean social learning do not, in sum, provide strong evidence for culture. Other terms, such as social learning, vocal learning, imitation, and tradition may be applied in some cases without resorting to more complex and controversial terms.

Contrary to Vaesen's argument that humans are unique with respect to nine cognitive capacities essential for tool use, we suggest that although such cognitive processes contribute to variation in tool use, it does not follow that these capacities are necessary for tool use, nor that tool use shaped cognition per se, given the available data in cognitive neuroscience and behavioral biology.

Although the authors' ingenuity in identifying criteria for innovation for field studies is appealing, most field studies will lack adequate data. Additionally, their definition does not clearly distinguish innovation from individual learning and is vague about cognitive mechanisms involved. We suggest that developmental data are essential to identifying the causes and consequences of learning new behaviors.