Animal cognition is a hot topic. How do we know what other animals are thinking?
Well, actually, mostly we don’t. It’s still a young field and a tricky one. We often can’t be sure even what other people are thinking, even though we can talk to them directly and share the same language. ('Yuh, sure she said that, but did she really mean it? What is she actually trying to tell me?’) And animals don’t talk, at least in the usual sense, which makes it even tougher to know what they’re thinking. Furthermore, many animal species live very different lives from us, and so, as the philosopher Wittgenstein famously cautioned, even if they could talk, we probably would not understand what they had to say.
Nevertheless, trying to understand the mental lives of other species - to get inside their heads - is an active and exciting area of research, and, notwithstanding the above caveats, a lot of it, in fact, focuses on aspects of communication, sparked by the example of research on bat echolocation by Donald Griffin and others in the 1950s. They discovered how it is that bats can navigate in the dark, and not by special powers of vision, but by sound - by producing a continuous stream of high-frequency 'click’ sounds (that we humans can’t hear) while they fly (Figure 1) and then listening for the portions of these clicks that get reflected (echoed) back off obstacles in the environment. This work helped to illuminate the dark world of the bat and it catalyzed the modern era of research on animal thinking - what is often now labeled 'cognitive ethology’. Following Griffin’s lead , one entire branch of this field focuses on studying the communication systems of other species, believing as he did that these offer a privileged window into the workings of their minds.