a bonobo humanity?

I felt a bit disheartened a while back when a teenage lass I know and love declared to me that she ‘hated animals’. Worse, one of her aunties chimed in enthusiastically with, ‘yeah, I hate them too’. I wasn’t sure about taking these assertions seriously, especially the fifteen-year-old’s, but my suppressed response, apart from WTF???, might’ve been, uhh but you do know that you’re animals, right?

In fact I didn’t respond at all, being too taken aback, but I’m sure they knew they were animals, and yet…

Us and them thinking is commonplace. It’s a feature of any species of living thing that they’re concerned with other members of their species, both positively and negatively. We compete with members of our own species for resources, and we also share resources with our own species. We mate, and fight, with our own species. We try to impress our own, either by our scariness or our attractiveness, depending on circumstances. Other species just don’t matter so much to us, except insofar as we need them, or need to avoid them, for our survival.

I’m speaking for species in general here, but humans have learned something about other species that should make a big difference to us, and that is that all species are more or less related. We even have techniques which can tell us just how related we are. We know that we’re a bit more closely related to chimps than we are to gorillas, and that we’re a bit more related to gorillas than we are to gibbons, and that we share a much more common ancestor with tree shrews than we do with lungfish, but the important point is that we know that we’re related to every other organism in the biosphere, without which not, as they say. So to hate animals, if you really mean it, is to be self-defeating in a big way.

And hatred, or dismissiveness, towards other animals, surely comes from an unthinking us-and-them position, a position that needs to be continually questioned and challenged.

I recently read the excellent Shadows of forgotten ancestors by Carl Sagan and Ann Druyan. Much of it, especially the second half, is devoted to demolishing claims to human specialness, our separateness from ‘animals’. They do so mainly by examining the lives and behaviour of other primates. Much of the following will derive from their book. I will start with the most general claim, and then look at some specific ones

Humans are different from all other animals, not just in degree, but in kind.

This ultimate us-versus-them claim is questionable in many respects. It usually comes with particular examples: we are the only ones who have x, or can do x, therefore…

But are we the only ones with property x, and if we are, where does this property come from? Humans, we know, are primates. We share a common ancestor with chimps and bonobos going back six million years. Are we different in kind from that common ancestor? If, for argument’s sake, we say that we are, at what point did that qualitative, rather than quantitative, difference emerge? We are still unable to clearly trace our descent back to that common ancestor, but we have plenty of example of earlier hominids to chose from – this site offers some 20 distinct species that might have been along the line of descent. Which one, if any, represented a qualitative transformation? Or do incremental quantitative changes somehow amount to a qualitative transformation? If so, how many changes, and, again, when exactly did the quantitative become qualitative? I don’t think these are fruitful questions, and the more we learn about other species, the more these questions dissolve away.

We share the properties of other animals in many ways, but I’ll pick on sex as one of the clearer examples. Humans long ago realized that the castrating of war captives rendered them less aggressive – though they would’ve had little idea why. They did of course know why such a practise rendered then incapable of producing offspring, another signal benefit. The removal of the testes, whether in humans, cats, dogs, sparrows or quails, has much the same effect; aggression is reduced, as are various other male traits governing behaviour towards females and towards other males. The reason is that the testicles produce most of the androgens – that’s to say the steroids or sex hormones, such as testosterone. The action of testosterone and other sex hormones is strikingly similar across all animal species. Experimenters have added or removed the hormones with increasingly predictable results, not only in mammals and birds, but lizards and fish as well. This isn’t to say, though, that the males of all these species, when their sex hormones aren’t interfered with, are always the more aggressive or dominant gender, for that depends on how much, and what types, of the sex hormones are naturally produced or released. Male and female wolves, gibbons and tree squirrels are about equally aggressive. Species have, over time, developed the ‘right’ hormone levels for their kind – that’s to say, the most adaptive. Give certain birds too much sex hormone, and the males sometimes end up killing each other, and overall numbers fall. In all of this humans are no different.

Of course patterns of sexual behaviour vary among mammals. Most mammals only mate when the female is ‘in heat’, during a particular phase of the estrous cycle, the estrus phase, which precedes ovulation. Menstruating females, though – the menstrual cycle is a subset of the estrous cycle, in which endometrial material is shed during menstruation – including a number of primate species, are not confined in their sexual activity to a particular period [so, no, we’re not the only ones with that ‘freedom’]. Interestingly, though, human societies often have prohibitions against sex during the menstrual period, whereas in other primates, sexual activity actually increases at this time. One of the wonders of human culture.

Humans are the only creatures that make tools

We only need one solid counter-example to demolish these general claims, and in this case we have several to choose from, but I’ll opt here for a very well-attested one; the use of reeds, straws or vine branches by chimps to catch termites. Not all chimps are able to do this, and few are able to do it really well (we tend to forget, with other species, apart from the domestic ones we deal with every day, that they have their bright sparks and their half-wits just as humans do), but it’s a highly developed skill which human researchers haven’t been able to develop. What’s more, it’s a skill that takes years to develop, and older chimps teach it to the young. What chimps have to do is find just the right kind of tool for the job – that is, to be manipulated down a termite hole and retrieved from the hole with as many termites clinging to it as possible, to serve as a dish worthy of the effort and expertise. This requires matching the tool to the termite burrow, which means knowing the characteristics of the various mounds in the neighbourhood, and then having the dexterity, not only to get the tool into the hole with the minimum of disturbance to the termites but, more importantly, to be able to twist it and move it to attract termites to the ‘intruder’, and then withdraw it without knocking all the termites off. If chimps can’t find the right shape and size of tool, they can and do modify it to suit the job, which is no different in kind from early humans modifying stones for cutting and for use as weapons. Such stones are our first well-attested tools, though only, of course, because stone outlasts other materials. This activity is far from simply opportunistic. It requires planning and foresight, and it’s certainly not the only example of tool use in chimps or in other animals, including birds.

Humans are the only self-aware animals

We have to be careful, of course, not to define ‘self-awareness’ and other related concepts in such a way that they can only apply to humans. Similarly, I can think of ways of defining the term which would make it inclusive of a great many species. Because of the great difficulty of accurate definition here, it’s quite useful, as a first approximation, to use a crude, behaviourist approach to the problem, such as the well-known mirror test – first applied, though in a non-rigorous way, by Charles Darwin. All of the great apes can pass this test, as can elephants, some cetaceans, and, probably most surprisingly, European magpies. They all fail the mirror test initially, but soon learn that they’re looking at their own reflection. Humans don’t pass the mirror test before the age of eighteen months, on average – though there are some problems with the reliability of that measure because of possible flaws with the classic mirror test which I won’t go into here. Suffice to say that learning to use mirrors for grooming, etc, is pretty solid evidence of self-awareness in other species.

Humans are the only species able to conceptualize

‘It would be senseless to attribute to an animal a memory that distinguished the order of events in the past, and it would be senseless to attribute to it an expectation of an order of events in the future. It does not have the concepts of order, or any concepts at all.’ [Stuart Hampshire, philosopher]

The above sort of observation, though it wasn’t actually an observation, was commonplace in philosophy well into the 20th century, but research into ‘comparative cognition’ has largely blown this bias away, as you might expect, with a bit of thought. After all where does conceptualisation come from if it isn’t an evolutionary development over time and species? Of course the concept of concepts is a bit murky, but researchers have been able to distinguish three types of concept learning – perceptual, associative and relational – and a more sophisticated type of concept-formation called analogical reasoning. A 2008 survey of the research found that many non-human species were capable of the first three types, with only the higher primates showing evidence of the fourth.

Humans are the only species with language

‘Language is our Rubicon, and no brute will dare to cross it.’ [Max Muller, 19th century linguist]

There has long been a great debate about this one, and much research and effort put in to trying to teach the rudiments of language to chimps and bonobos. Sagan & Druyan dwell at length on this work, though well-known linguists such as Charles Hockett and Steven Pinker suggest that there is a bigger divide than sometimes admitted between other primates and humans in this area. Again, this depends on how tight, loose or technical your definition of language is. Still, no matter how language is defined to exclude non-humans – such as arbitrariness between sound and meaning, and discreteness in the construction of terms – researchers manage to find evidence of it in other creatures. Nobody denies that language  has reached a pinnacle of sophistication with humans, but again there are many traces of complex communication in many other species, and it’s of no value to us to try to reduce their import. The Muller quote above indicates how our preoccupation with our own superiority can lead to a hostile attitude to any knowledge that dares to threaten it.

Humans are the only creatures who know they will die.

We know from an early age that we will die largely because of our sophisticated communications. We learn of the history of our culture, peopled with dead contributors, we see monuments to the dead everywhere, the disappearance of aged pets and relatives is patiently explained to us. Other animals, without these communications, may still feel it in their bones as the time approaches. There’s certainly evidence for mourning in elephants, chimps and many other animals.

Humans are the only ethical animals.

Ethics and social living are an almost essential pairing. The Biblical commandments that still make sense to us are all about making society more predictable and therefore more bearable to us as individuals, which is why they’re common to most religions and cultures. Whilst it may be argued that humans are more consciously and explicitly ethical than other social animals, some recent research has cast doubt on our freedom to choose our ethics. We appear to be driven, genetically, to preserve ourselves and our own, and to rationalise an ethical system around that drive. Other creatures have evolved the same drives and act in similar ways to ourselves.

Humans are the only animals that possess culture

If you think of culture as a process, rather than working back from cultural products, it would be hard to deny that this process exists in many other species. I’ve already pointed out that simple tool-making is passed down from adult chimps to children. This is cultural transmission, and is a basic factor in all culture. Basic tool-making and teaching were presumably the first forms of cultural transmission in humans.

Humans are the only creatures who explore their own origins, and the origins of all else

This may well be the last bastion, but again it doesn’t represent a difference in kind – even supposing that such explorations don’t occur to non-human minds. These types of explorations are the culmination of increasingly sophisticated concept-formation, meme-transmission and theoretical and technological development. With all this, knowledge, ideas and speculations are converging on us at an ever-increasing pace. It’s no surprise, therefore, that the idea of a ‘singularity’ has captured our imagination, tenuous though the idea might be. Interestingly, the idea of the singularity is another instance of quantity building up to a sudden ‘flip’, a qualitative transformation. Another self-serving and self-congratulatory idea perhaps?

We humans are quite fascinating, the more so the more we examine ourselves, but we are learning that what we’re made up of is the same stuff that other life forms are made of, and the similarities are every bit as instructive as the differences. We’re a distinct species, no doubt, but it is counter-productive to think of ourselves as a species apart.