What makes a biological species such an intriguing concept is its stasis. From out of a near maelstrom of biological and evolutionary dynamics—selection, genetics, generation—a species emerges as something obstinately distinct, stable and enduring. Darwin himself was puzzled that nature does not formulate instead into a mish-mash of morphologies and traits, with a more gradual and more frequent variation across space and across time. This puzzlement—an aspect of what is often referred to as Darwin's dilemma—has never been completely resolved. Modern explanations for nature's tendency to coalesce into well delineated and persistent species usually center around the notions of reproductive isolation and costs of rarity, but in many respects these accounts miss a good deal of the point. A species is not only static and conservative in its morphology and reproductive viability, a species is also static and conservative in its overall behavior, to the point of being almost perfectly predictable across the entirety of its existence. If for instance one were to film a documentary on almost any plant or animal species, place it inside a vault for a hundred thousand years, one could then remove the documentary and promote it as still accurate and up-to-date, without the slightest need of an edit. This dogged constancy across the entire reach of the phylogenetic network appears to be the evidence of an underlying biological invariance—a law if you will—a law that has not been adequately determined.
And to make the matter yet more puzzling, there is the one notable exception to the law, the one case of the law having encountered a blatant violator—that is, the human species.
Humanity certainly did not begin as the most obvious counterexample to the notion of species stasis. The genus Homo and its predecessors had for millions of years been unfolding into an entirely standard set of stable and generally durable groupings: afarensis, africanus, habilis, ergaster, erectus, heidelbergensis, neanderthalensis. And for quite some time Homo sapiens too appeared to be slated for the same usual course, its members passing through typical and mostly unvarying animal lives within the more hospitable corners of the African continent. But it was around fifty thousand years ago that an unprecedented behavioral transformation began to take shape within the species, a transformation that has only accelerated throughout the intervening years and today shows no signs of abatement. In the early twenty-first century almost no characteristic of human behavior would be recognizable to anyone who could have observed or recorded man's earlier days on the savanna. And although it is indeed behavior that constitutes the most clearcut difference between the humans of today and the humans of the past, with the advent of everything from dental implants to artificial knees, from Viagra to augmented bosoms, from in vitro fertilization to stem cell technologies, it is evident that much of the morphological and reproductive intransigence still lingering within the human species is now on the verge of disappearing as well.
And so there are two questions to be investigated regarding the concept of a biological species: one, what compels a species, across all its generations, to maintain such consistent and stable behavior, and two, how is it that the human species has managed to escape this compulsion?
To better understand the behavior of a species, perhaps the best place to begin is with Immanuel Kant. Kant was the first to fully confront the challenge of describing how a behaviorally productive biological consciousness can arise from the continuous multitude of sensory impressions that each organism receives, impressions that in their rawest form would be little more than chaotic and overwhelming, would be little more than useless noise. Kant's approach, including its heavy reliance upon syllogistic logic, was perhaps not entirely adequate to the task (C.S. Peirce would later improve the framework greatly). Nonetheless, Kant's groundbreaking effort still manages to capture the essence of what would have to be incorporated into any proposed solution to the problem, namely a recognition that in order for biological consciousness to exist at all, an organism's multitude of sensory impressions would have to be unified under some kind of structure or rule. Or to put it in the parlance of modern data science, each organism's raw sensory input would have to be sorted, filtered, mapped and reduced, resulting finally in the kind of perceptual foregrounding and targeted awareness that could serve as the basis for productive behavior. Kant's depiction is too often taken to be merely philosophical or as applicable to human reasoning alone, but in fact it is most informative when applied biologically: the early pages of the Critique of Pure Reason outline a general framework whereby a manifold of biological stimulus can be transformed into a precise and targeted response, something no lion on the prowl could ever do without.
Kant was also the first to recognize that the means of any sorting, filtering, mapping and reducing would have to be provided (a priori) by the organism itself, and that the general form of these means would be the primary determinant of the organism's perceptual content (and therefore the primary determinant of the organism's resulting behavior). Kant often used the somewhat vague and magical-sounding term faculty to delineate these organism-provided means, but of course it has to be remembered that Kant was writing well before the advent of Darwin, Mendel and an accurate rendition of Earth's biological timeline, so some vagueness and magic are to be excused. Today, post the advent of Darwin, Mendel and an accurate rendition of Earth's biological timeline, the a priori means that underlie sensory unification and perceptual grounding are now richly detailed and more deeply understood, having shed their vagueness upon a wealth of observable information regarding biochemistry and genetics, and having cast off their magical aura behind a well described evolutionary process that has spanned hundreds of millions of years. In the biological kingdom, what drives the means for sorting, filtering, mapping and reducing, what shapes the structure and rule behind stimulus unification and targeted response, are the ongoing requirements of survival and procreation—physically manifested within each organism's biochemical structure and honed into effectiveness through enormously long stretches of selection and generation.
The capstone of Kant's description, his list of conceptual categories—organized under such headings and subheadings as quality, quantity, modality, plurality, negation—was arrived at in an attempt to achieve maximum generality. But in a certain sense all this ardent abstraction overshoots the mark when applied in a biological context, where really only concreteness will do. If one were to search from the treetops of the Amazonian rain forests all the way to the depths of the ocean floor, it would be a frustrating endeavor to find anywhere a biological consciousness unified around such notions as quality, quantity, modality, plurality, negation. And yet it would be little more than child's play to find a biological consciousness unified around such notions as food, water, danger, shelter, family, sex, predators, prey, conspecifics. It is biological need that determines the primary structure of biological perception, and it is the pervasive and unyielding impulse behind these biologically driven categories that provides the first indication of why biological behavior remains so consistent and stable. Survival ceaselessly asserts its decrees, procreation fervently presses its demands, evolution ruthlessly carries out its mandate, and each organism, both outwardly and inwardly, must adhere to these strict regulations or else disappear. And so in broad and inexorable lockstep, the members of the biological community aim their rapt attention towards food, water, danger, shelter, family, sex, predators, prey, conspecifics—and then respond accordingly, and respond mostly the same.
Of the biologically driven categories, conspecific awareness and recognition holds special significance: it is the primary catalyst—at least within the animal kingdom—behind each species developing a strong tendency to coalesce, both territorially and behaviorally. Each organism appears to possess a predisposition to foreground first and foremost those sensory impressions that are directly associated with the other members of its species—lions perceive and attend primarily to other lions, geese perceive and attend predominantly to other geese, ants perceive and attend chiefly to other ants (and of course humans perceive and attend first and foremost to other humans). The principal inducement towards this nearly universal characteristic is that it is the most direct solution to an otherwise haphazard reproductive challenge. Successful mating requires that male and female conjoin at the same time and at the same location, a rendezvous that would be made problematic, if not downright impossible, should each member of the species be unable to distinguish and foreground its own kind from all the remainder—a perceptual blindness that would be practically guaranteed without inherent conspecific awareness, since there is nothing within sensory impressions by themselves that would help promote one class of perceptions over another. Even in those rare cases where organisms live solitary lives and egg-laying and fertilization are separated in time, the species is still bound together by the perceptual foregrounding of the expected location of egg-laying and fertilization, in this instance an effective proxy for conspecific prominence.
And beyond the logistical requirements of procreation itself, many species make heavy use of conspecific foregrounding to advance a broad range of beneficial behaviors. Nurturing of the young for instance necessitates that adults carry a perceptual preference for the offspring of their own kind—lest lions find themselves randomly rearing goslings, geese find themselves indiscriminately raising ants, and so on. Successful foraging, pack hunting and herd defense all depend upon a keen perceptual attention to the other members of the population, even when those members occupy no more than a minuscule portion of the entire sensory field. But perhaps most importantly of all, conspecific awareness and recognition allows tried-and-tested species behaviors to be passed along from generation to generation without the inefficient obligation that each and every behavior be imprinted genetically or made completely instinctual. The maturing members of many species go through a period of time in which their main occupation is to scrutinize parents, siblings, extended family and other models within the population, imitating observed activities and eventually taking on those activities with an increasing faithfulness (and thereby becoming models for the next generation). This recurrent cycle of learned and transmitted behavior is always confined to the species itself—lions do not learn from leopards, geese do not model sparrows, no organism imitates non-biological objects. Each organism is a fully engaged student of its own kind—and is nearly oblivious to everything else.
Thus the trait of conspecific awareness and recognition has both the powerful and the restrictive impact of making a species insular. Conspecific foregrounding encourages the species to cluster, it turns the species' members inwards for mutual protection and predatory assistance, and it promotes generational continuance of the species' more successful behaviors. But the unrelenting narrowness of this characteristic also has the consequence of effectively blinding the species to any alternative information the sensory field might have to offer—whether that information would come from other species or from the non-biological world. Nearly all sensory impressions not directly connected to the species itself or to the immediate requirements of survival and procreation are relegated to the sensory background and never gain perceptual prominence, and thus never influence biological attention or behavior. As a result, the species is provided little opportunity for change, since perceptually speaking nothing ever differs from generation to generation. So powerful and so confining is the impact of conspecific awareness and recognition that it really needs to be considered an essential part of the definition of a species, for a species is determined not only by its morphological similarities and its reproductive sufficiency, it is also determined by the mutual awareness and recognition of all its members, the glue that holds the species together and assures its unvarying continuance.
The inherent perceptual inclination towards conspecifics, along with the corresponding disinclination towards other species, suggests there is a boundary between these two extremes. On one side of the boundary, conspecific awareness and recognition must function within a certain range of tolerance, for despite there being varying levels of genetic and morphological difference among species members, conspecific foregrounding remains active and strong in nearly all population circumstances. But this tolerance clearly has its limits, because it does not extend so far as to include the other species, and thus it can be assumed that as conspecific distance increases between organisms (a function most likely of increased morphological and/or genetic difference), a boundary is eventually reached where the tolerance is fully extended and then finally exceeded, with a corresponding attenuation and loss of conspecific awareness and recognition.
These concepts of conspecific distance, tolerance and boundary play an important role in assessing the expected outcome and impact of an organism that introduces genetic alterations into a species. A new genetic signature carrying differences that are only minor in effect and/or infrequent in number will likely leave the bearer within the conspecific tolerance range, meaning that the bearer will experience typical conspecific foregrounding and typical conspecific perceptions and behaviors, improving the chance for continuation of these minor mutations. This must happen to some extent with nearly all offspring, because each organism possesses a genetic signature that is unique to some degree, and yet in the large majority of cases this uniqueness does not interfere with conspecific awareness. By contrast, a newly introduced genetic signature that carries differences that are major in effect and/or frequent in number increases the likelihood that the conspecific distance between the bearer and the other members of the species will become so large as to strain or even surpass the conspecific tolerance range, thereby weakening or even nullifying conspecific awareness and recognition. To take an extreme example, one might imagine a lion being born with such an exaggerated level of genetic mutation that it is effectively a leopard, meaning that this newborn and its “conspecific” neighbors are destined to become perceptual strangers, with survival and procreative consequences almost certain to turn negative. Even at much lesser extremes of conspecific distance, challenging biological consequences can still be anticipated, and thus conspecific distancing almost certainly plays a role in the thwarting of significant genetic change within a species, another manner in which conspecific awareness and recognition contributes to the ongoing stasis of a species.
Although the odds of continuation are indeed negligible for an organism outside the conspecific tolerance range, the prognosis is more uncertain, and in some ways more intriguing, for an organism approaching the boundary—near enough that conspecific awareness and recognition is weakened to some degree but not so near as to make survival and procreation essentially impossible. There are several distinguishing characteristics that can be predicted for such an organism. Mating for instance, although not precluded, will certainly be more problematic, since the organism's inherent perception for potential mates, as well as their perception in turn for it, will be more hazy than is the case for the rest of the species, leading to coupling behaviors that might seem distant or strange. In species that make heavy use of conspecific foregrounding for mutual defense or combined attack, an organism stretching conspecific tolerance will of necessity be a weaker participant in these group activities and might come to be regarded as an encumbrance by way of result. And perhaps most importantly of all, the maturation process for a conspecifically distanced organism will almost certainly be more difficult and more delayed than for its peers, its relative inability and disinclination to scrutinize others in the population and to imitate their behaviors hampering the typical transmission of species behaviors. Such an organism will not only physically be an outsider to the population, it will also perceptually and behaviorally be an outsider as well.
On the other hand, the challenges faced by an organism near the conspecific border do provide the potential for an ironic compensation. It needs to be remembered that the primary purpose behind an inherent form of biological perception is to unify sensory impressions, impressions that would otherwise remain chaotic, overwhelming and useless. And to the extent that an organism's perceptual mechanisms are diminished by its biological circumstances, the corresponding unification of sensory experience will be diminished as well. Such weakening of sensory unification will likely give rise to an assortment of sensory difficulties—hypersensitivity, hyposensitivity, synaesthesia. In order to ameliorate these difficulties, a conspecifically distanced organism, detached in significant degree from one of its primary means of sensory unification, will be driven towards alternative means of sensory unification—which is to say, it will be driven towards alternative means of perception. This effectively opens the door to a wider awareness of alternative features within the sensory field, such as those provided by the other species, and more significantly, those provided by the non-biological world. It is well known that the non-biological world provides a rich framework of organizing principles that can serve as the basis for unification of sensory experience, principles that go under such names as symmetry, repetition, pattern, structure and form. These organizing principles are in theory available to all organisms, but the restrictive effect of biological perception in general, and conspecific awareness and recognition in particular, usually pushes awareness of these non-biological features well into the sensory background. And thus ironically, it is only the organisms that get loosened from the strictures of conspecific awareness and recognition that gain the opportunity to foreground these alternative features from the surrounding environment, and thereby gain the perceptual freedom to achieve a broader and deeper awareness of the entire sensory field.
If there were only one such conspecifically distanced organism or even a few such organisms extant within a population, there would likely be little impact on the species as a whole. But if the population were to possess a significant number of such organisms, and that number were to remain stable for a reasonable period of time, the species dynamic could begin to change. All the necessary conditions for a change would be in place: the broader population would have a conspecific relationship to the population's more distant members (albeit a looser relationship than normal), and the more distant members would have access to a wider array of perceptual experience. The natural workings of conspecific awareness and recognition would prompt the broader population to begin to notice the new behaviors and new perceptions being originated by the more distant members, an awareness that might even encourage imitation. In this manner the enhanced perceptual experience of the population's more distant members would begin to infiltrate the perceptual experience of the species as a whole, and with a change in species perception would come a corresponding change in species behavior. In defiance of the universal expectation of a continual species stasis, this species would be on the verge of a behavioral revolution.
Of course considering the biological fragility that haunts the conspecific boundary, and observing the non-changing behavior of all the species to be found in the natural world, it would seem that any talk of behavioral revolutions being driven by conspecific distancing would have to qualify as little more than academic exercise, some hypothetical musing. And indeed that would be the end of the matter, if it were not for the one piece of unfinished biological business—namely the one species that has emerged suddenly and prominently as a blatant violator of the tenets of species stasis, the same one species (not coincidentally) that has broadly expanded its perceptual experience of the sensory world, the same one species (not coincidentally) of which it can no longer be said that it is to be found in the natural world. The human species.
The behavioral revolution of the human species has been nothing short of stunning in both its scope and its speed. There is little in the way of hard evidence to suggest that prior to around fifty thousand years ago Homo sapiens individuals lived much differently than all the other animals—riding the ebbs and flows of survival and procreation, gazing out upon an entirely natural landscape, confined to the African continent alone. And then suddenly everything began to change. Art, symbolism, categorized tools, sophisticated weaponry—all began appearing in ever increasing numbers and with ever advancing technique. Humans began to spread geographically and did not stop until the entire planet had been covered. They extincted many other species along the way and bred a chosen few into a domesticated abundance. Today, very few humans gaze out upon an entirely natural landscape—artificial environments have become vastly the human norm.
One notable aspect of this human revolution is that has been accompanied by—indeed it has been driven by—a broadened perceptual awareness of the sensory world, including a much broadened perceptual awareness of the non-biological world. Nearly all the changes that have become the hallmark features of modern human existence have been built upon a backbone of non-biological constructs, everything from the grammatical patterns of language all the way to the structured symmetries of towering skyscrapers. Literally everywhere one looks, one finds the profuse application of the organizing principles of pattern, symmetry, repetition, structure and form, principles that never would have reached the surface of human ken not that long ago, but today constitute the proliferating and artificial embodiment of man's ever burgeoning intelligence.
Thus the characteristics of the human behavioral revolution can be seen as matching the description given above for a species change brought about by the influence of conspecific distancing. The enormous human behavioral change has been accompanied by an equally enormous human perceptual change, by an expanded perceptual awareness, one that goes far beyond the restrictions of biological perception alone. Humans still have their conspecific awareness and recognition for one another, and they still possess their sensory instincts for survival and procreation, but humans are no longer confined by these perceptions, the species has been freed entirely from its former perceptual prison.
The predictions of conspecific distancing would suggest that this liberation must have been catalyzed through the influence of a significant and stable sub-population of conspecifically distanced humans, relative outsiders who driven by biological and sensory necessity would have been the first to explore a different means of seeing the world, the species' pathfinders to expanded forms of perception. And so the question needs to be asked: within the human population, is there a recognizable subgroup of members who can be seen as carrying the distinguishing characteristics (including the challenges) of a conspecifically distanced organism and who also possess the compensating trait of an expanded perceptual awareness, an awareness that often shies from typical biological perception but that gravitates more readily to alternative perceptual targets, targets such as the non-biological world and its organizing principles of pattern, symmetry, repetition, structure and form?
Within the human population, there is indeed such a group of people, and over this past century they have begun to be recognized. They are defined most accurately as autistic.
Autism has been giving the scientific community a very difficult time. The condition was first regarded as extremely rare and almost always debilitating, but as evidence has mounted over the years it has become more and more clear that at least one percent of the human population can be described as autistic, and along with such numbers has come the inevitable corollary that in the large majority of circumstances the condition cannot be all that debilitating. Autistic individuals certainly face some challenges, challenges that can vary in degree, but that has never prevented autistic individuals from blending in with the rest of the human population, so much so that they have gone virtually unrecognized for dozens of millennia. Nonetheless, even in the face of these accumulating facts, the scientific community has been unable to let go of its need to medicalize the condition, somehow convinced, without evidence, that autism must be the result of biological defect. And so the research and studies have been growing like weeds, searches for defective genes, searches for defective neural pathways, searches for defective metabolisms—massively funded and massively peopled efforts that have now become laughable in the combined fruitlessness of their results. And more troubling still—and certainly more shameful—has been the scientific community's willingness to heap insult and torture upon its autistic subjects, branding them with an assortment of inaccurate and unsupported labels (burdens, tragedies) and stifling them with an assortment of damaging treatments and so-called cures (applied behavioral analysis, stupefying drugs). The scientific community's present approach to autism is destined to become one of that community's more humiliating hours.
A far more accurate approach to understanding autism is to regard it as a condition of increased conspecific distance. All the core characteristics of autism—what nearly every autistic individual shares in common—are the very same characteristics predicted of an organism that is much nearer to the conspecific border than the majority of its peers. Autistic individuals, although very much a biological part of the human population, show less inclination for and less attention to their conspecific neighbors, a trait which is often taken as evidence of damaged social functioning but upon careful observation is more precisely described as a diminished human awareness, an attenuated human recognition. Autistic children, less inherently prone to the activities of conspecific observation and conspecific imitation, mature more slowly than their non-autistic counterparts, sometimes taking well into adulthood to assume a fuller role within the broader population. Autistic individuals experience an assortment of sensory anomalies—hypersensitivity, hyposensitivity, synaesthesia—conditions that seem to have no discernible physical cause and no tangible consistency from individual to individual, evidence that these anomalies stem not from physical defects but instead from a more generalized difficulty with the attainment of sensory unification. Finally, and almost invariably, autistic individuals compensate for their diminished conspecific awareness and recognition by concentrating instead on alternative perceptual targets, including a predominance of targets from the non-biological world. In the youngest autistic individuals this is most often seen in the rapt attention given to such things as spinning objects, symmetrical figures, repeated sounds and scenes, and in older autistic individuals this characteristic often coalesces into specialized and deeply learned interests. Sadly, the term repetitive and restricted behaviors is often used to disparage these concentrations on alternative perceptual targets, betraying a complete misunderstanding of both their necessary purpose and their liberating consequence. For these concentrations on alternative perceptual targets are both the creative antidotes to what might otherwise be an overwhelming sensory chaos, and they are also the opening doors to the organizing and intelligence-producing principles of pattern, symmetry, repetition, structure and form.
The key role that autistic individuals must have played—and are continuing to play—in the sparking of the human behavioral revolution can be seen in the oddly consistent feature that has emerged at each point of human perceptual and behavioral change. These changes are always launched by individuals and their discoveries (never by groups), individuals who are inevitably in possession of a distinguishing and uncommon set of traits. From Socrates to Newton to Beethoven to Einstein—and at each transforming moment of genius in between—the human revolution has been powered by individuals who seem to be mostly detached from the typical concerns of society and species, and who are instead obsessively focused on alternative concerns, often non-biological concerns, concerns that the rest of the population might describe as worthless or strange. It has never been much of a secret that the personal characteristics of genius tend to be rather odd; all that is being noted here is that these personal characteristics tend to be odd in a predictable and recognizable way. One might call these individuals of genius autistic, or one might call them conspecifically distant—there really is no difference—but the true mark of their genius is that they see the world not as it is and as others perceive it, the true mark of their genius is that they see the world exactly not as it is and exactly not as others have already perceived it, the same compensatory and distinguishing characteristic of a conspecifically distanced organism, of an autistic individual.
Any explanation of the human behavioral revolution would need to be an explanation of coincident events, because it was at the exact same moment in Earth's enormous biological/evolutionary timescale that humans quite suddenly underwent an entire host of unprecedented transformations:
- They began perceiving aspects of their sensory world that
went far beyond the elements of survival and procreation alone.
- They began behaving less and less like the animals they had
formerly been, and more and more like the modern humans they were
about to become.
- They began constructing artifacts out of the material
structure of the non-biological world.
- They began displaying the tangible signs of what would become
an ever increasing intelligence.
- They began expanding geographically, conquering climates and
other species, and did not stop until they had blanketed the entire
The common explanation for the human revolution, that it is simply a by-product of normal biology and normal evolution, fails to tie together any of these multi-faceted events and fails to address their suddenness and simultaneity. The notion of conspecific distancing, however, has the merit of encompassing nearly all these different aspects of the human revolution: it provides a direct and observable source for the expansion of human perception; it contrasts that new perception with biological perception, providing an explanation for humanity's departure from animal behavior; it clarifies mankind's sudden interest and skill with the elements of the non-biological world; and it describes humanity's ever increasing intelligence as the embodied reliance upon the organizing principles of pattern, symmetry, repetition, structure and form.
Furthermore, conspecific distancing associates directly to yet another event coincident with the human revolution. Concurrent with the other changes taking place within the species, Homo sapiens was undergoing a significant introgression of genetic material from Neanderthals and perhaps other human sub-species, an introgression sizable and pervasive enough that nearly all non-African humans living today possess around a 2 to 3 percent admixture of non Homo sapiens genetic material (Green et al., 2010). There is still much to be learned about the nature and impact of this introgressive event, but it is clear such an occurrence would be exactly the kind of genetic jolt that could loosen the conspecific bonds of a species and potentially give rise to many generations of conspecifically distanced individuals.
All these simultaneous and fast occurring events, along with the nature of the autistic population living today, serve as the strong circumstantial evidence that the human behavioral revolution was not an event of normal biology and normal evolution, but instead was an event driven by the characteristics of conspecific distancing, characteristics that ultimately gave rise to an evolution-shattering and universe-unveiling aberration—the lone counterexample to the law of species stasis.
Green, R.E., et al. (2010). A draft sequence of the Neandertal genome. Science 328, 710–722.