What distinguishes us from animals? A much less trivial question than expected

When I wrote recently about the fact that the use of tools is not a trait of our species or of the presence of a culture or an intelligence, I deliberately drew the attention of readers to the fact that whenever we look for elements that create a clear discontinuity between our species and other animals, we end up discovering that in reality, just like when trying to distinguish one human race from another, there is no abrupt discontinuity, but rather a continuous development of the section under examination, which does not allow caesuras that are not arbitrary. As happened when Darwin highlighted the evolutionary continuity between primates and man, the concept of the biological and behavioral contiguity of our species to others, which is observed whatever the trait we intend to examine, is difficult to accept, because making distinctions between us and others, whether humans or animals, is the basis of group recognition in every social species, and is therefore a trait that is inextricably linked to the evolution of our prosocial brains. The other of the defense of one’s identity, in politics as in biology, is the search for differences, for impassable ditches that allow the recognition of the other as one’s own kind.

Now, the point is not that there are no appreciable differences between animal species: the point is that these develop along a continuous spectrum, for the simple reason that the process that produced them, by selection of genomes, biochemistry and morphotype, is an evolutionary process that started from the available biological material to create more or less quickly new varieties. Given these theoretical considerations, the reader could rightly object that the “quantum leap” between our species and the others is of a cultural and cognitive nature; but even in this case, just as in the case of the production of tools and technologies of other species, it should be remembered that culture and cognition of our species were preceded by those of many others.

If we look, for example, at the visual and musical arts, we can see examples in species other than our own, such as the Neanderthals, who preceded them; and if it is true that many of us do not know how to paint or play, as probably happened to them, it is immediately difficult to assume as a distinctive trait of an entire species knowing how to perform those cultural activities more or less well. Knowing why the stars shine is probably a trait that at most identifies a certain number of people with modern Western scientific culture; but this is no more a useful trait to characterize all individuals of our species, present and past, than writing the Divine Comedy or a sonata. However, one might observe, more widespread skills, such as linguistic skills, are everyone’s possession. Yet, compositional language, with its syntactic and grammatical rules, has also been demonstrated in other animals, like birds; but more importantly, again, thinking it’s a trait unique to sapiens overlooks the fact that other hominins were probably as skilled as we are.

So what are the traits that could unequivocally distinguish individuals of our species? With Desmond Morris, one could answer that they are the primary and secondary sexuality traits, i.e. those which – coincidentally – allowed the rise of our species through reproductive isolation from previous hominid populations. While they evidently don’t work 100 percent, given that we’ve mixed with Denisovans and Neanderthals, they are distinctive enough to allow for a near-perfect barrier. But there’s more. If we measured with a suitable metric, invented by Shannon, the information content which each individual of our species makes use of, which processes and which generates, moreover building on a previous heritage, probably, for reasons not necessarily linked to greater potential than even to very close species, but to the simple demographic and historical development of our species, if we made that measurement we would discover that the quantity of information in which our minds move is orders of magnitude higher than that of other species. The information produced and consumed is one of the true traits that distinguish us; information not necessarily true or directly useful, but always intelligible, modifiable and transmissible by every individual of the sapiens. This trait, from an adaptive point of view, is what got us where we are; not better or worse, and in any case destined to come to terms with the limits of development, but certainly immersed in the extended phenotype of our world of data, meanings and signs.