Extended Ontogeny
Extended Ontogeny: A Hypothesis on Transient Structures in Personality Development
Abstract:
This paper investigates whether the logic of embryonic development – wherein transient, evolutionarily inherited structures (such as pharyngeal arches, the postanal tail, lanugo, and the yolk sac) are normal only as long as they retain their temporary status – can be extended to the postnatal development of personality. Using embryology as a starting point, it is shown that developmental pathologies (such as a persistent tail, syndactyly, or congenital hypertrichosis) arise not from the mere existence of a vestigial structure, but from a failure in its timely transition: its reduction, transformation, or the exhaustion of its one-time function.
The paper then hypothesizes that a similar structural principle applies to the motivational, cognitive, and cultural dominants of personality. Processes such as play, reproductive drive, resource accumulation, and status or conformity programs are analyzed as evolutionarily inherited "transient complexes." These are necessary at specific stages of personal development but are not intended to constitute its final organization. This hypothesis is examined alongside the traditions of philosophical anthropology, cognitive linguistics, evolutionary biology, and developmental psychology (including Portmann, Bolk, Gehlen, Groos, Maslow, Loevinger, Cook-Greuter, Kegan, Tomasello, Dawkins, and Lakoff). Crucially, the methodological limits of this transfer are established: the analogy applies to the interpretative principle of development rather than to any literal equivalence of specific traits.
The concept of the "false finale" is introduced as a key term, defined as an individual's fixation on one of many evolutionarily inherited, local motivational "attractors" mistaken for the ultimate goal of existence. Unlike normative stage-based developmental theories, this hypothesis does not postulate a mandatory final stage. Instead, it points to the existence of multiple open-ended, non-normative developmental pathways as a heuristic possibility for further academic discussion rather than an established fact.
Extended Ontogeny
“I am, indeed, quite sympathetic towards the idea that human culture provides a new milieu in which an entirely different kind of replicator selection can go on.”
R. Dawkins, The Extended Phenotype: The Long Reach of the Gene[1]
Chapter 1. Transient Structures of Embryogenesis
1.1. Embryogenesis as Continuous Reworking
Popular literature frequently depicts human embryogenesis as a continuous, additive construction of the organism: a body with all its organs, systems, and proportions gradually emerges from a single cell. This picture significantly oversimplifies the complex of interdependent, successive processes that shape the organism. Development progresses not only through the emergence of the new, but also through the subsequent reworking of existing structures or the elimination of newly created ones. The developing organism temporarily constructs structures that either disappear, radically change their purpose, or persist merely as traces of an ancient architecture.
This process does not imply a literal repetition of the adult evolutionary lineage – a human being is never successively a "fish", an "amphibian", or a "reptile." This simplistic formulation of the old biogenetic law has long been discarded. During development, ancient and highly conserved programs are indeed activated: they form structures homologous to elements that perform different functions in other vertebrates. Subsequently, the human embryo remodels these structures in accordance with its own anatomical plan. It is this precise sequence – emergence, utilization, transformation, or reduction – that remains essential for our further argument.
The table below outlines some of the most prominent examples of transient embryonic structures:
These cases cannot be reduced to a single mechanism. Some structures undergo reduction (Type A); others serve as raw material for new organs (Type B); still others perform a brief but necessary function before yielding to the succeeding system (Type C). Thus, it is more precise to speak not of "useless vestigial organs", but of transient morphogenetic complexes, which are normal precisely because their existence is limited to a specific developmental window.
One of the most illustrative examples is the fate of the postanal tail. While the caudal region is clearly pronounced in the early human embryo, its axial elongation subsequently ceases, and its tissues undergo deep remodeling, in which apoptosis plays a major role. Consequently, by the late embryonic stages, only a tiny caudal remnant remains, associated with the future coccyx.[2]
Equally famous, though frequently misapplied as a direct reference to our aquatic ancestors, is the case of the pharyngeal arches. A human embryo does not develop fully functional gills like the respiratory organs of a fish. Instead, pharyngeal arches, clefts, and pouches form – elements of the ancient vertebrate pharyngeal architecture. While in fish these are linked to the gill apparatus, in humans they are remodeled into the structures of the face, neck, middle ear, and endocrine glands. This is not a complete discarding of the old; rather, the ancestral design receives a novel deployment.[3]
Interdigital tissue also demonstrates the corrective regulation of developmental pathways. Initially, the limb bud is a continuous plate of tissue. Selective cell death and remodeling then occur between the future digits. In this sense, fingers do not simply "grow" out of a void; their form is achieved by removing a portion of already existing tissue. This process is not a design flaw; it is a fundamental component of the normal morphogenetic program, wherein the true error is a failure to execute the corrective program.[4]
The successive transition of renal systems demonstrates that development occasionally requires the temporary functioning of ancestral apparatuses. In the fourth week of human development, the pronephros appears and rapidly regresses. Subsequently, the mesonephros is activated for a limited period, and only the succeeding metanephros becomes the foundation of the permanent kidney. Rather than a history of redundant repetition, this represents a series of linked organizational solutions in which the later system utilizes and transforms the outputs of the earlier one.[5]
The yolk sac is particularly vital for understanding this general principle. In humans, it lacks the obvious nutritive role it plays in oviparous animals, as embryonic nutrition is secured through other means. Yet, this does not render the yolk sac a meaningless vestige. In the early stages, it participates in hematopoiesis, metabolic processes, and the formation of the vascular system. It persists in mammals not because the organism "forgot" to discard it, but because an evolutionarily inherited structure was co-opted for a different, vital function, almost entirely disappearing once that role is fulfilled.
This logic can be framed through a programming metaphor: Natura does not rewrite an organism from scratch with every evolutionary shift in environmental conditions. It does not act like an engineer who discards an obsolete blueprint to draft an ideal design from first principles. Instead, evolution works with existing genetic and morphogenetic designs – transposing them into new conditions, altering the activation timing of their elements, and repurposing existing "tools." It maximizes the use of "legacy code", introducing patches to meet the demands of updated tasks (environmental challenges). The legacy design is never canceled; instead, it is overlaid with regulatory modifications, additions, and constraints.
Consequently, the morphology of a mature organism almost always carries elements of redundancy relative to its final form. The spinal column unfolds along an outdated but functional version of the axial plan before development halts further caudal growth; the limb is initially constructed as a solid plate before the interdigital tissue is cleared; the fetus is covered in lanugo, which is later shed. This is not a literal "code" or a conscious decision by nature, but a highly useful heuristic pattern: a historically established developmental program is more easily modified through regulation and remodeling than through the creation of an entirely independent architecture. In this light, regulatory changes that ensure the timely restriction or transformation of organs become paramount for the formation of a viable organism.
1.2. Three Destinies of a Transient Structure and Their Disruptions
In normal embryogenesis, a transient structure is not required to vanish without a trace. It can meet one of three destinies: reduction, transformation, or integration into a new system in a subordinate role. It is crucial not to conflate these three scenarios, as they are fundamentally distinct:
(a) Reduction via programmed cell death: The structure plays a brief scaffolding role and is then systematically eliminated, as seen with the postanal tail and interdigital webs;
(b) Co-optation with a complete transformation of function: The structure does not disappear but is remodeled, changing its original purpose to a qualitatively different one – such as pharyngeal arches transforming into the jaw, auditory ossicles, and larynx;
(c) Temporary functional deployment followed by near-complete regression: The structure functions fully in the early stages to perform a role that will later become redundant, only then undergoing regression – exemplified by the yolk sac, whose ancestral nutritive role is lost, but whose early hematopoietic and metabolic functions remain critical.
We must highlight this observation, as it is central to our subsequent argument: Throughout ontogeny, the organism systematically constructs complexes of structures that reflect its evolutionary history and represent an inherited, largely legacy toolkit. These complexes are not developmental errors – they are necessary scaffolds or raw materials for subsequent stages. However, at a specific point, they must either transform into structures meeting the organism’s updated needs, be reduced to a vestigial trace, or regress after exhausting their temporary function. The problem arises not from the existence of these complexes, but from a failure of transition: if a transient structure fails to reduce, transform, or conclude its one-time role in a timely manner, it traps the organism in an earlier developmental configuration at the expense of its mature form.
Developmental pathologies make this principle visible, demonstrating how normal outcomes depend on the precise execution of reduction, division, and transformation. For instance, the retention or formation of a tail-like appendage in the lumbosacral region is a rare congenital anomaly. Syndactyly (the persistent fusion of adjacent digits), caused by disruptions in the genetic pathways regulating interdigital cell death and limb patterning,[6] similarly illustrates the vital role of embryonic remodeling.
Finally, rare forms of congenital hypertrichosis lanuginosa demonstrate the consequences of disrupting the shedding mechanism of temporary hair. Normal lanugo is typically replaced by later vellus and terminal hair; its persistent retention points to specific genetically determined conditions.[7] In genetic literature, one such condition – Ambras syndrome, associated with a rearrangement of chromosome 8q – is discussed directly in connection with the concept of atavism: the reactivation of an ancestral morphological trait, rather than a mere localized arrest of development (Ambras syndrome is likely closer to the reactivation of a silent genetic program than to a simple failure of scheduled apoptosis, as seen with the tail or webbing).
These examples are valuable not as a catalog of pathologies, nor as a pretext for attributing an "incomplete animality" to humans. Their significance lies elsewhere: each marks with anatomical precision a specific stage where a transient structure failed to make its prescribed transition and remained frozen in the body. A scaffolding structure thus usurps a permanent presence instead of maintaining its proper transit status. These examples show that the mature human form does not emerge through the simple accumulation of ever-newer parts. It demands a timely shift in regulatory regimes and priorities: some structures must disappear, some must yield their autonomy, and others must serve as raw material for a more complex organization.
At this juncture, we arrive at the central question of this paper: Do similar processes continue after birth – no longer on a genetic foundation, but on a memetic one; not with the tissues of the body, but with cultural complexes, motivational systems, behavioral patterns, and aesthetic or ethical preferences that direct human cognitive and creative capacities and orient the deployment of our energy?
Chapter 2. Extending Ontogeny: From Morphology to Motivation
2.1. From Diogenes' Rooster to the Question of Maturity Criteria
According to a historical anecdote preserved by Diogenes Laërtius[8] (who lived in the 3rd century CE, roughly six centuries after the events described), Plato defined man as "a featherless biped." Upon hearing this definition, Diogenes of Sinope plucked a rooster, brought it into the Academy, and declared, "Behold, Plato's man!" This prompted the Academy to append to the definition: "...and with broad, flat nails."
This story warrants reflection before we outline the concept of extended ontogeny. Plato did not err in his observation – bipedalism and the absence of feathers do indeed distinguish humans from most living creatures known to him. The error lay in the very method of definition: Plato sought a trait that could be exhibited and verified at a glance – a morphological rather than a functional or biographical criterion. Diogenes did not disprove the observation; he demonstrated its insufficiency by presenting an object that formally satisfied the definition yet was recognized by no one as its referent. The Academy’s response – adding "broad, flat nails" – is telling because it was an attempt to patch the definition with yet another morphological trait, rather than to revise the defining principle itself.
The philosophical significance of this episode lies in its demonstration of how any morphological criterion of human identity can be satisfied without one being a human being in any substantive sense. Plato sought an external, observable mark; Diogenes showed that a list of traits is not a definition, but an open-ended index that must be continuously patched with new caveats for every new counterexample. Interestingly, this same principle – necessary but individually insufficient modifications using existing materials rather than a fundamentally new, bespoke design – governs human embryogenesis: patches and replacements eventually yield a finished, mature organism. However, as Diogenes' rooster demonstrates, a mere catalog of morphological traits possesses no such sufficiency – and this distinction is crucial when we ask whether personal, postnatal human development exhibits a similar convergence.
From this logic, a distinct conclusion follows: if morphology is an insufficient criterion even for the adult human body, then the physical functionality it provides is even more insufficient as a measure of personal maturity. The body can be presented and "signed off" in a single examination – growth is complete, the skeleton is formed, the reproductive system is functional – and in this sense, physical maturity has an unambiguous, observable answer. But the moment the question shifts from the body to the personality, the same approach – exhibiting and signing off at a glance – fails. There is no precise moment, credential, or medical index that allows us to declare "this personality is now mature" in the way an X-ray confirms "this skeleton is fully ossified." The question "what is a human being" should therefore be reframed as "where does human development end", an inquiry that demands an expansion of both ontological and methodological analysis.
2.2. The Asymmetry in Assessing Prenatal and Postnatal Phases
Embryonic development is evaluated by a clear criterion: a fetus is considered mature and healthy if transient structures inherited from our evolutionary past – gills, tails, lanugo, webbing – have successfully transformed or vanished by the time of birth. No transient structure is ever deemed sufficient to conclude that "the fetus has matured"; on the contrary, its persistence past the term is a diagnostic sign of developmental disruption. Crucially, this criterion does not require us to know the exact utility of a given transient structure at its respective stage – it is enough to establish the fact: it was supposed to regress or transform, and it did (or did not) do so in a timely manner.
Postembryonic personality development rarely receives such a methodology. A person is conventionally deemed adult and fully formed if they can independently manage a basic set of life tasks: securing adequate resources, maintaining social relations, and reproducing – regardless of which motivational and behavioral complexes continue to dominate their personality. In other words, our conventional and even clinical understanding of personality maturity is almost entirely functional rather than structural: we care only whether the individual copes with life's demands, not at what psychological cost or through what motivational architecture. Two individuals who manage the basic demands of adult life with equal success are judged equally mature, even if for one, solving these tasks consumes their entire existential horizon, while for the other, it represents a long-passed stage that has yielded to entirely different pursuits.
We must avoid overstating the conceptual novelty of this idea – it would be an error to claim that psychology has never viewed postnatal development as a sequence of stages: existing stage models of development (Piaget, Erikson, and others) are well established and cannot be ignored. However, virtually none of these models analyze early stages as transient instruments that must transform or yield their dominant position; a vestigial status is traditionally ascribed only to physical, never to motivational or cognitive, structures. Piaget’s stages describe shifts in cognitive operations, while Erikson’s stages describe successive psychosocial crises, but neither scheme asks the embryological question: What exactly must happen to the structure of the preceding stage – must it disappear, transform, or assume a subordinate role – for that stage to be deemed successfully resolved rather than merely left behind by chronological age? Furthermore, how pathological is a failure in this transitional mechanism? It is this structural criterion, rather than the mere concept of stages, that is proposed here as an extension of the term. We suggest not a new sequence of stages, but a new criterion for evaluating what occurs at the boundary between them.
2.3. Postnatal Complexes and Their Probable Destinies
By analogy with the table of embryonic structures, we can attempt to frame postnatal motivational complexes within the same logic – as structures characterized by an original function, an expected destiny, and a signature pathological fixation. Before presenting this table, a methodological caveat is necessary: unlike the table in Chapter 1, where every row rests on established embryological facts, this table represents a structured outline of a hypothesis proposed for academic discussion, not an established empirical mapping. The table below lists prominent examples whose symmetry of form does not imply an equal symmetry of proof: embryological data are verifiable by the methods of embryology, whereas claims regarding the "normal destiny" of motivational complexes are philosophical extrapolations requiring their own independent argumentation, which will be developed below.
We should examine the structure of the table itself: in every row, the pathological fixation is not some external, alien program, but the very same program deprived of its timely transition mechanism. The infantilization of leisure is not a breakdown of play motivation, but its normal operation extended past the window in which it was functional. The same holds for the other examples: pathology in each model is never an imported defect; it is the original mechanism that simply failed to halt or transform on schedule.
In this context, referencing the problem of obesity is a truism – it arises not so much from the availability of poor-quality food, but from the transformation of a basic physical need for nutrients into a primary source of positive affect and a fundamental method of structuring time (as Eric Berne would define it). I cite this example only because this primary pathology has triggered a cascade of secondary ones: the obsession with fitness, which initially served to burn excess calories and compensate for sedentary lifestyles, has devolved into a cult of the body where form triumphs completely over substance. The original pursuit of physical beauty (recall the Greek athletes) has collapsed into hypertrophy and physical distortion. Each of these examples is structurally identical to the embryological patterns in Chapter 1: pathology arises not from a foreign pattern, but from a failure of its internal limiters and correctors to activate.
2.4. "The Discreet Charm of the Successful Norm"
None of the typical adult orientations – parental care, financial stability, professional career, athletics, or social recognition – is a pathology in itself. The issue is not one of "right" or "wrong", but of a structural criterion: Does this complex serve the further development of the personality as a transient, instrumental tool, or does it usurp the status of a terminal, self-sufficient goal beyond which the personality ceases to move?
Let me illustrate this with an observation from my own social circle. Among my acquaintances is a family: he is a highly successful software engineer with three decades of experience, and she is a diligent office administrator. Both confidently navigate life's challenges, managing whatever surprises or relocations our unpredictable contemporary era throws their way. I have repeatedly observed that whenever they succeed in improving their material well-being and securing their future, their focus remains confined within the parameters of the very problems they have just solved. Their interests never ascend to the higher tiers that, according to Maslow's theory, should emerge as a superstructure in their motivational hierarchy. Instead, this couple’s energy is channeled into expanding and exploiting the comfortable plateau they have secured. For them, "new" means variety within familiar categories; "better" lies in variations of the repeated. Consequently, despite financial independence and ample leisure time, in their fifth decade of life, their cultural horizon is defined by highly refined but narrow consumer skills – such as knowing the precise temperature at which a restaurant waiter should serve a bottle of wine, or selecting a resort with the optimal service-to-cost ratio. Yet, both are thoroughly pleasant conversationalists – generous, hospitable, well-mannered, and well-educated within their social milieu.
I highlight this example because of a crucial detail: it is not the obstacles of objective hardship or social struggle, but rather their complete and stable competence within a cozy, well-secured niche that makes their case philosophically interesting. This is not a story of failure, but of a success that has looped back upon itself. These individuals remain valued, productive members of society; they are simply an illustration of a structural pattern where a lateral, auxiliary branch of development stabilizes as the main highway instead of yielding to the next phase. Crucially, any external observer evaluating them by standard metrics of adult success would find no flaw. The asymmetry of assessment discussed earlier is manifest here: by conventional standards of maturity, they are exemplary adults.
2.5. Precursors and Parallels
The arguments of extended ontogeny do not claim to be invented from a tabula rasa; they enter into dialogue with established traditions in philosophical anthropology and developmental psychology. Below, these traditions are examined not as a formal bibliography, but as independent attempts to articulate the same underlying intuition from various angles – developmental embryology, philosophical anthropology, motivational psychology, and ego development theories – even if none of them explicitly formulated the precise structural criterion (transient instrument versus terminal goal) proposed here.
Adolf Portmann introduced the concepts of physiologische Frühgeburt ("physiological prematurity") and extrauterines Frühjahr ("extrauterine spring") in his work Biologische Fragmente zu einer Lehre vom Menschen[9]. He argued that compared to other higher mammals, the human infant is born roughly a year premature and requires an extrauterine year to reach a comparable stage of development. This phase, relocated outside the womb, exposes the human infant to cultural and social shaping. The significance of this observation is profound: if Portmann is correct, the boundary between embryogenesis and postnatal development is biologically artificial. A substantial portion of the developmental work completed in utero in other mammals continues in humans through active interaction with the world and culture. This aligns with our thesis that human ontogeny structurally extends past birth in a very literal, biological sense.
Louis Bolk proposed the theory of fetalization[10], noting that adult humans morphologically retain embryonic or juvenile traits of primates – such as a flat face, sparse body hair, and cranial proportions. Stephen Jay Gould expanded and popularized this concept of neoteny in Ontogeny and Phylogeny[11]. The neotenic lineage was subsequently advanced by Ashley Montagu in Growing Young[12], who linked neoteny not only to anatomy but to the retention of "juvenile" motivations – such as curiosity, playfulness, and social attachment – into human adulthood. For the current concept, this second, Montagu-inspired shift is vital: if neoteny shapes not only the skull but the very architecture of motivation, then the thesis of a prolonged, plastic postnatal development receives an independent foundation.
Arnold Gehlen, in Der Mensch. Seine Natur und seine Stellung in der Welt[13], introduced the concept of the Mängelwesen – the "deficient", biologically incomplete being. Unlike animals, humans lack specialized organs and rigid instincts, forcing them to compensate for this biological deficit through culture. In Gehlen’s view, this deficiency is not a flaw but a design feature that opens a space for the cultural completion of what biology left unfinished. This matches our thesis: the cultural and motivational evolution of personality is not an optional addition to biology, but a direct continuation of the same fine-tuning process that begins in embryogenesis. The only difference is that at this postnatal stage, the material of adjustment is no longer just the genetic program, but accumulated culture.
Karl Groos, in The Play of Animals and The Play of Man[14], established the "practice theory of play." He argued that play is not a purposeless discharge of excess energy, but an evolutionarily selected training mechanism for instincts and skills before they are required in earnest. This provides a precise foundation for the first row of our table: play motivation has a clear ontogenetic function and, by its very nature as training, implies a decline in its dominance once the skill is mastered. Training flights must scale back precisely because the training was successful, not because it failed.
Abraham Maslow’s hierarchy of needs is popularly depicted as culminating in self-actualization. However, in his 1969 paper The Farther Reaches of Human Nature[15], Maslow added a higher tier – self-transcendence – indicating that even self-actualization was not his terminal point of motivational development. Crucially, this modification was made by the author himself, not by subsequent commentators: the creator of the hierarchy did not view the penultimate stage as the final one. In this sense, the late Maslow is closer to the logic of this paper than the early, textbook Maslow.
Ken Wilber (Integral Psychology; Sex, Ecology, Spirituality)[16] describes development as a sequence where each succeeding level must "transcend and include" the preceding one – preserving it as part of a wider structure rather than displacing it entirely. Crucially, Wilber notes that pathology arises not merely from fixation, but from transcendence and repression – when a more mature level attempts to suppress or deny the previous one rather than integrate it. This parallels embryogenesis, where a successful outcome is rarely outright destruction but is instead co-optation: pharyngeal arches become the jaw and larynx rather than vanishing. Wilber's formula is closer to Type B in our embryological typology (co-optation with functional transformation) than to Type A (pure reduction).
Jane Loevinger[17], Susanne Cook-Greuter[18] и Robert Kegan[19] developed independent but closely related models of ego development. In Loevinger's model, the final stages are the Individualistic, Autonomous, and Integrated stages; Cook-Greuter, extending this model, adds a later stage termed the Unitive. Kegan works within a different framework – focusing not on named stages but on the "subject/object" relationship: that which entirely governs a person's perception from within at one stage becomes available for conscious examination (as an object) at the next. The common theme among all three authors aligns with our central thesis: development moves toward liberation from complete identification with earlier ego structures (though their specific terminologies and architectures differ and should not be conflated). Kegan’s metaphor of "subject becoming object" structurally mirrors embryogenesis: that which was once the very tissue of the organizing process (the subject of development, dissolved within it) becomes material open to conscious remodeling (an object viewed from without). This represents another independent line of thought leading to our structural principle.
Michael Tomasello (The Cultural Origins of Human Cognition; Becoming Human; A Natural History of Human Morality)[20] demonstrates that uniquely human capacities – such as shared attention, collective intentionality, language, and moral norms – are forged gradually during childhood development and represent a continuation of the species' evolutionary history.
Richard Dawkins, in The Selfish Gene[21], introduced the concept of the meme – a unit of cultural information that is replicated, mutated, and selected within a "meme pool" much like a gene in a biological gene pool. In the context of this paper, this observation is essential for one reason: it provides the developing motivational and value complex of personality with a second, independent medium of inheritance alongside genetics. In this view, the personality does not merely unfold an innate motivational architecture across different settings; from birth, it is embedded in a local memetic landscape – a fragment of the wider cultural landscape – from which it draws a largely contingent, historically accumulated set of cultural structures, just as the embryo unfolds historically contingent genetic material. Both media, genetic and memetic, operate on the general principle described in Chapter 1: they are not custom-designed for each new carrier but are inherited and remodeled, carrying legacy elements whose utility has expired alongside elements that remain functional. In this sense, extended ontogeny unfolds in two parallel inheritance media simultaneously, and the pathology of the "false finale" described in Chapter 3 can anchor itself in either: as a fixation on an outdated biological motivational program, or as the uncritical retention of an obsolete meme-complex inherited from the cultural environment in which the individual was raised.
An even more significant parallel is found in the cognitive linguistics of George Lakoff, particularly in Women, Fire, and Dangerous Things[22] and his earlier collaboration with Mark Johnson, Metaphors We Live By[23]. Lakoff and Johnson demonstrate that the abstract concepts humans use to describe themselves and the world are systematically constructed upon physical, sensorimotor experience: affection is conceptualized through the physical warmth of an embrace ("affection is warmth"), joy and increase through upward direction ("happy is up", "more is up"), understanding through vision ("understanding is seeing", culminating in the literal "I see"), and cognitive categories themselves through the spatial schema of a container, where something is either "inside" or "outside" a boundary. None of these concepts exist in the infant’s experience as ready-made abstractions; each is built upon a simple, physical sensation (skin warmth, gaze direction, the sensation of bodily boundaries within the womb) and only later, through development, detaches from the physical situation to describe matters entirely unrelated to physical heat, height, or vision. The science of heat – thermodynamics – emerged only after the embodied concept of "hot/cold", born from somatic experience, detached from the body and became a formal abstraction capable of generating entirely new meanings.
Importantly, this process – which is the very architecture of abstract thought rather than a mere literary device – is structured exactly like the processes described in our embryology chapter: the physical, sensory foundation of a concept is neither discarded nor declared false when the concept expands its scope. Instead, it is co-opted, integrated into a more complex, abstract architecture as an ancestral, no longer autonomous scaffold. It follows a path identical to Type B in our first-chapter typology, where pharyngeal arches do not vanish but are remodeled into jaws and larynxes. Lakoff, in other words, demonstrates the mechanism of extended ontogeny at the level of conceptual thought: what begins as a product of a physical body’s sensory receptors is capable, without severing its somatic roots, of developing into propositions describing matters that transcend that body entirely.
2.6. Extending the Criterion
Given that transient morphological structures are normal elements of biological ontogeny, we can hypothesize that transient motivational, cognitive, and cultural dominants play a similar role in the ontogeny of personality. In this view, personality maturity is defined not by the absence of these programs, but by whether they retain their status as transient instruments of development or freeze into the ultimate goals of existence. The conceptual transfer occurs at the level of the developmental principle itself, rather than through literal equivalents: we are not claiming "tails equal greed", but rather that "the status of a transient tool, which threatens to become a terminal goal if transition fails", is shared by both levels of organization.
If the human psyche continues to carry a motivational architecture inherited from ancestral species – the drives to survive, reproduce, and elevate status within the group – then these tasks are structurally analogous to embryonic organs: they explain the origins of motivation, but they are not required to define the highest organization of a mature personality. A large portion of evolutionary psychology describes the psyche as an instrument dedicated to servicing these ancestral tasks. The proposed hypothesis does not deny their role in explaining where motivation comes from, but it questions their right to serve as the metric of maturity.
Thus, our earlier question can be reframed: not "what makes a human being morphologically human", but "where does personal development end?" Our preliminary answer is that it does not end with the achievement of any single plateau – reproduction, status, or accumulation – but continues as long as these plateaus retain their status as resolved, instrumental stages rather than terminal destinations.
Chapter 3. Pathologies of Extended Ontogeny
3.1. What Is at Risk If the Transition Fails
If a structure in embryogenesis fails to complete its prescribed transition – if it is not reduced, transformed, or does not conclude its temporary function on time – it traps the organism in an outdated developmental configuration. The first two chapters analyzed this logic from different angles: embryology provided documented physical structures, while personality psychology offered a hypothesis rooted in philosophical anthropology. For millions of years, the tail helped our ancestors maintain balance and survive; for tens of millions of years, the gill apparatus supplied older ancestors with oxygen – and neither was an error in its time. The error would be if development arrested at the tail or the pharyngeal arches – that is, if a structure useful at its stage refused to yield to the next simply because remaining in the old form was comfortable or familiar.
Similarly, securing shelter, producing offspring, accumulating resources, and achieving social status are not errors in personality development. The error arises if an individual, having resolved these tasks, continues to loop within the boundaries of the same motivational space instead of releasing resources to form structures that no longer serve survival and reproduction, but instead define the cultural, intellectual, and creative boundaries of the personality. In such cases, the individual does not grow qualitatively new structures; on the contrary, they hold onto rudiments, maintaining archaic elements instead of letting them yield to the next stage of organization.
Crucially, this "holding onto" implies not a passive state, but an actively maintained configuration: retaining a transient structure in place of a final one requires constant, if subconscious, effort. In teratology, the retention of an embryonic structure past its deadline is not an absence of process, but the active disruption of one process (timely reduction) in favor of the persistent execution of another (the original functioning of the structure).
3.2. A Symmetric Classification of Deviations by Severity
The key methodological tool for establishing a precise symmetry between the two ontogenies is not the "reduced / transformed / retained" criterion itself, but the degree to which a departure from the normal pattern threatens the subsequent development of the system – the organism in one case, the personality in the other. This methodological shift allows us to classify deviations by their systemic consequences rather than their mere presence, making a genuine rather than decorative symmetry possible.
At the embryological level, deviations fall into two classes of varying severity. Minor deviations do not threaten the overall viability of the organism and are easily corrected surgically or resolved on their own. Lanugo typically sheds within a few weeks of birth even if its reduction is delayed; a persistent tail is easily removed surgically without lasting consequences; cutaneous syndactyly does not prevent the development of a healthy organism and is routinely corrected. In these cases, the danger arises not from the localized deviation itself, but only when it is a symptom of a broader genetic disruption – as when severe, symmetric syndactyly of the hands and feet combines with craniosynostosis and distinct facial features to form Apert's syndrome, where the systemic nature of the disorder, rather than the digital web itself, poses the threat.
Major pathologies, by contrast, affect structures where embryogenesis permits no arrest at an intermediate form. The pharyngeal arches must not end as a gill apparatus; they must remodel into the jaw, auditory ossicles, and larynx. The aortic arches must remodel into the definitive vascular system; the notochord must reduce, leaving behind the nucleus of the intervertebral discs. Any major deviation in these structures leads to severe defects that compromise viability, and if sufficiently pronounced, render the fetus entirely nonviable.
A clear pattern unites both classes of deviations: the most dangerous cases are not those where a structure simply lingers, but those where a structure actively involved in building the organism fails to change its developmental trajectory. It continues to execute an ancestral, legacy vector instead of yielding to a remodeled, mature form. The difference between lanugo and the notochord is not their origin, but how far the consequences of their delay ripple outward: in one case, the delay is localized and reversible; in the other, it is woven into the very architecture of the body’s construction.
By this same logic of severity rather than the mere presence of a program, we can propose a symmetric classification for the mental level of extended ontogeny – with the caveat that this remains a heuristic expansion of the principle. Minor deviations are motivational and behavioral programs that continue to occupy a prominent place in an adult's life past the "typical" window, but do not block the development of other personality structures and are generally adjustable by the individual or with moderate support. A prolonged adult attachment to play behavior – collecting, gaming, athletic hobbies – does not prevent intellectual and creative development as long as it remains one dimension of life rather than its sole axis. Delayed status motivation in a specific professional setting operates similarly: it is not pathological unless it becomes the exclusive axis of self-definition.
Major pathologies are cases where a central, organizing motivational structure of the personality does not merely linger, but completely replaces the subsequent architecture of the personality. Intellectual, ethical, and aesthetic dimensions of existence become entirely subordinate to a single inherited program. Just as pharyngeal arches must become jaws rather than remaining gills, resource accumulation, sexual hunting (reproductive activity), status competition, or the pursuit of natural impressions must be remodeled into something qualitatively different rather than continuing indefinitely in their original form. Their fixation as the sole organizing structure of the personality is the mental equivalent of an embryonic structure failing its prescribed remodeling, triggering a systemic rather than isolated disruption.
The common thread in both dimensions of this symmetry is clear: the danger is created not by the presence of an inherited program, but by its transformation from a transient, instrumental role into the permanent, all-encompassing organization of the system – be it the organism or the personality. This criterion, rather than the mere presence or duration of a program, is the central diagnostic sign of a false finale.
3.3. Structural Parallel: A Comparative Summary
The final row of this table marks a deliberate and fundamental departure of the proposed model from most existing theories of personality development: it is not claimed that all individuals inevitably reach a creative, trans-biological stage (as in some readings of Maslow or Wilber). It is asserted only that such a stage represents an open evolutionary possibility rather than a mandatory milestone. This distinction – between "possible" and "inevitable" – is the primary boundary separating our concept from classical stage theories, which often slid into a normative "should." Furthermore, we suggest avoiding the term "stage", which implies a rigid, mandatory sequence. Instead, we recommend using the term evolutionary attractors – forces that continuously "attempt" to seize the organizing role of the personality, but which need not be resolved in a specific order, or resolved at all. An individual can be barely touched by an attractor, linger near it for decades, return to it repeatedly, or live their entire life within its boundaries – in all cases, the attractor remains the same; what changes is the place it ultimately occupies in the architecture of the personality.
3.4. Why We Must Avoid Repeating Maslow's Normative Error
Abraham Maslow was repeatedly criticized for the normativity of his model, which described not only how people do develop, but how he believed they should develop. As a highly educated humanist, Maslow universalized the developmental path he personally valued most. He did not fully account for the fact that the vast majority of people are entirely comfortable stopping midway up his hierarchy, feeling no urge to ascend further. Subsequent research revealed a far more diverse landscape than he envisioned: many individuals have no drive toward self-actualization in the Maslowian sense; high creative achievements frequently coexist with unmet basic needs; individuals can be driven simultaneously by motives from different levels; and many feel no need to transcend the boundaries of family, status, profession, or material comfort.
The proposed model seeks to avoid this error. It does not claim a mandatory developmental trajectory that all must complete. It asserts something less categorical but more universal: humans possess a multitude of evolutionarily inherited, local goals (attractors), each of which strives to become final. The maturity of a personality is defined not by which of these goals it has realized, but by whether it has preserved the capacity to move beyond any of them.
By stripping away the limitations of stage theories in the vein of Piaget, Erikson, or Maslow, we arrive at a theory of false finales: evolution has left humans with numerous intermediate waystations, each capable of masquerading as the ultimate destination. The difference is fundamental: stage theories describe a sequence one must pass through; the theory of false finales describes traps one must know how to escape, without prescribing any single correct route between them. Personality maturity is defined not by completing a pre-programmed developmental agenda, but by preserving the capacity to step outside established motivational regimes – a view that structurally echoes the concept of freedom not as a choice among existing alternatives, but as the capacity to generate entirely new spaces of possibility.
3.5. The False Finale as the Key Concept of Extended Ontogeny
The three chapters of this paper converge on a single conclusion from three distinct angles. Chapter 1 demonstrated through embryology that organic development is not an additive accumulation of parts, but a sequence of creating, utilizing, and overcoming transient forms – and that a failure in this transition, rather than the existence of the transient structure itself, leads to teratological outcomes. Chapter 2 proposed transferring the evaluative principle of these structures to postnatal personality development. It showed that philosophical and psychological traditions – from Portmann and Gehlen to Maslow and evolutionary theorists – have independently gravitated toward this intuition without explicitly framing it as "transient instrument versus terminal goal." This chapter completes the argument, showing that both pathology and normality in both domains answer to a single criterion: not the presence of an inherited structure, but its failure to yield to the next.
The pathology of extended ontogeny is not the existence of inherited motivational programs; these are inevitable and necessary, like embryonic pharyngeal arches or a temporary tail. Pathology is the lock-in of one of these programs as the absolute, ultimate goal of existence, when that program is merely one of many lateral branches of development with no inherent finality. It is this specific figure – not an absence of evolution, but its arrest at an intermediate, locally attractive, but non-final point mistaken for the destination – that this paper terms the false finale of extended ontogeny.
If this conceptual transfer is justified – and this paper proposes it as a heuristic hypothesis rather than an established fact – it carries a practical and modest implication. Maturity does not demand the abandonment of play, accumulation, status-seeking, attachment, or reproduction, just as embryogenesis does not demand the abandonment of pharyngeal arches or the notochord. It demands something else: not mistaking an exit ramp for the highway, not treating a rest stop as the destination, and preserving – regardless of what has been achieved and settled – the capacity to move forward toward a transcendent point that, by its very nature, recedes with every step we take.
Therefore, we conclude with an observation addressed not to philosophy in the abstract, but to every member of the species Homo sapiens sapiens who is prepared to continue their development rather than declare it complete. Neither the morphological finality of the body nor a highly refined system of goal-setting – no matter how perfected or socially approved – justifies treating development as finished. The former was exposed as an insufficient metric long ago by the story of Plato's rooster; the latter is challenged by the same structural principle this paper has traced through embryogenesis and the pathologies of extended ontogeny.
Every mastered behavioral pattern, every polished system of reacting to the world, is by definition a structure that has served its purpose for a completed stage. It represents not a monument to achievement, but raw material for subsequent remodeling: what was yesterday's highway may today be merely a segment awaiting co-optation into a more complex order – just as pharyngeal arches do not vanish but find a new purpose in the jaw and larynx. The diversification of what has been mastered is neither its abandonment nor its devaluation, but the very transformation through which a transient structure justifies its existence. Maturity, in this sense, is not a milestone to be claimed once and for all, but an unceasing readiness to discover within our most polished tools the potential for their own transcendence.
© Valentin Lokhonya
Sumy, Ukraine, July 2026
https://doi.org/10.5281/zenodo.21381937
References and Sources
[1] Dawkins R. The Extended Phenotype: The Long Reach of the Gene. Oxford University Press, 1982.
[2] A study on the development and regression of the human tail (review of persistent human tail cases). PubMed: https://pubmed.ncbi.nlm.nih.gov/39636098/
[3] Review of the development, evolution, and derivatives of pharyngeal pouches and clefts. PubMed: https://pubmed.ncbi.nlm.nih.gov/20144910/
[4] A study on interdigital tissue regression (apoptosis in hand formation). PubMed: https://pubmed.ncbi.nlm.nih.gov/27752097/
[5] Embryology of the urinary system (pronephros, mesonephros, metanephros). NCBI Bookshelf: https://www.ncbi.nlm.nih.gov/books/NBK559309/
[6] Review of the genetic mechanisms of syndactyly. PubMed: https://pubmed.ncbi.nlm.nih.gov/35549993/
[7] Review of congenital hypertrichosis lanuginosa (including Ambras syndrome). PubMed: https://pubmed.ncbi.nlm.nih.gov/23793217/
[8] Diogenes Laërtius. Lives and Opinions of Eminent Philosophers, Book VI (Life of Diogenes of Sinope).
[9] Portmann A. Biologische Fragmente zu einer Lehre vom Menschen. Basel: Schwabe, 1944.
[10] Bolk L. Das Problem der Menschwerdung. Jena: Gustav Fischer, 1926.
[11] Gould S. J. Ontogeny and Phylogeny. Cambridge, MA: Belknap Press of Harvard University Press, 1977.
[12] Montagu A. Growing Young. New York: McGraw-Hill, 1981.
[13] Gehlen A. Der Mensch. Seine Natur und seine Stellung in der Welt. Berlin: Junker und Dünnhaupt, 1940.
[14] Groos K. The Play of Animals. New York: D. Appleton, 1898; Groos K. The Play of Man. New York: D. Appleton, 1901.
[15] Maslow A. H. The Farther Reaches of Human Nature. Journal of Transpersonal Psychology, 1969, vol. 1; книга — New York: Viking Press, 1971.
[16] Wilber K. Sex, Ecology, Spirituality: The Spirit of Evolution. Boston: Shambhala, 1995; Wilber K. Integral Psychology. Boston: Shambhala, 2000.
[17] Loevinger J. Ego Development: Conceptions and Theories. San Francisco: Jossey-Bass, 1976.
[18] Cook-Greuter S. Postautonomous Ego Development: A Study of Its Nature and Measurement. Doctoral dissertation, Harvard University, 1999.
[19] Kegan R. The Evolving Self: Problem and Process in Human Development. Cambridge, MA: Harvard University Press, 1982; Kegan R. In Over Our Heads: The Mental Demands of Modern Life. Cambridge, MA: Harvard University Press, 1994.
[20] Tomasello M. The Cultural Origins of Human Cognition. Cambridge, MA: Harvard University Press, 1999; Tomasello M. A Natural History of Human Morality. Cambridge, MA: Harvard University Press, 2016; Tomasello M. Becoming Human: A Theory of Ontogeny. Cambridge, MA: Belknap Press, 2019.
[21] Dawkins R. The Selfish Gene. Oxford University Press, 1976.
[22] Lakoff G. Women, Fire, and Dangerous Things: What Categories Reveal about the Mind. Chicago: University of Chicago Press, 1987.
[23] Lakoff G., Johnson M. Metaphors We Live By. Chicago: University of Chicago Press, 1980.