The Tricky Problem with Other Minds
Human “exceptionalism” is for many people an unquestioned assumption. For the religious, it is a God-given fact; for humanists, it is a celebration of our unique mental capacities. No other species has created music, art, literature, or built skyscrapers, or imagined going to the moon and figured out how to go there and how to get back. No other species has found treatments for common illnesses and fatal diseases. We are the only animals that use language to share inner experiences with one another.
Our unique features emerged through changes that made us different from our primate and other mammalian ancestors. The fact is, we continue to change over time. If our species survives long enough, future humans will be different from us, and perhaps new human species, with yet unimaginable capacities, will emerge.
Every species is, by definition, different. We care about our differences because they are ours. But from an evolutionary perspective across the long history of life, our traits are not better or more valuable than those possessed by any other organism.1 They are just different.
One of our purported differences is a source of much debate. And that, of course, concerns the nature of the human mind. To what extent do our mental states overlap with and diverge from those of other species? No one would ever confuse the body of another animal with that of a human. Even our closest primate relatives have bodies that are distinct from ours. Yet we freely attribute mental states similar to those we experience to other animals.
Charles Darwin struggled with this problem as he tried to reconcile his biological theory of evolution with his strong opinions about the mental life of animals. He claimed that there are “no fundamental differences between man and the higher mammals in terms of mental faculties”2 and viewed animal emotions as mental states comparable to those experienced by humans.3 His writings were peppered with free-wheeling comments about animal consciousness based, not on science, but on common sense and folk wisdom—that is, by assuming that what goes on in the mind of a human is similar to what is happening inside the head of other animals in similar situations.
Scientifically we don’t really know what, if anything, other animals experience.
During the Victorian era in which Darwin lived, anthropomorphism was rampant in the young science of animal behavior (in part because of Darwin’s influence), and also in popular culture—the novel Black Beauty, about a horse who narrated his mistreatment by humans, was a best-seller. Darwin’s ideas about the relation of animal bodies to ours was revolutionary, but he was lock-step with common wisdom when it came to animal mentation.4
When asked why he viewed animal behavior in terms of human experience, given that his more standard approach was to trace how humans are like other animals, Darwin responded by saying that it was “more cheerful,” and “less off-putting,” to think of the animals in human terms than to treat humans as having “beastial” qualities. Many have commented on Darwin’s short-comings in this area. For example, in a history of psychology, Fred Keller pointed out that “Darwin bestowed a mental life upon man’s cousins with a very open hand without the self-critical zeal that marked his biological endeavors.”
