Because of horses' unique intelligence (dawn horses had advanced brains, according to paleontologists), as well as social and emotional commonalities with humans, behaviorists are able to conduct tests to determine horse perception. It's been revealed that horses can interpret two-dimensional images, much as humans can. And although they are far-sighted and partially color blind, they recognize different human faces, even being able to tell twins apart, and, more important perhaps, perceive emotions. When we gaze at a horse's eye, we also read his feelings. Could the Pleistocene cave artists have felt that connection as well? And perhaps in finding this bond, did a mutual trust develop even in prehistoric times? (Humans have famously abused the trust of our animal companions on too many occasions, but horses seem to have unending faith in us anyway, which just proves that they must know something we don't.)
In searching for a deeper understanding of horses, Williams explores some of the mysteries in their evolution, including one fascinating riddle: the disappearance of the horse in the Western hemisphere, and specifically North America, around 14,000 years ago. The reasons for this vanishing are debated vehemently by scientists, and no consensus has been reached. (The fact that horses were no longer here when Europeans arrived has been used as the rationale for the government's removing the wild mustangs in the West as a non-native species.) Darwin himself had struggled to find an answer to this phenomenon. Why, after millennia of adapting to the changing conditions, would the horse population dwindle and die out in this region? Was it the result of human activity?