Experiments are the key to understanding socially acquired knowledge in cetaceans

We agree with Rendell and Whitehead that cetaceans acquire knowledge from caretakers and peers, and that a clear understanding of this process can provide insight into the evolution of mammalian cognition. The passive observational methods they advocate, however, are inadequate for determining what cetaceans know. Only by experimentally investigating the cognition of cetaceans can we hope to understand what they learn through social interactions.