The Current Aging Paradigm
Science can’t evolve in a vacuum. All concepts must exist within a preconceived notion of reality. In his 1962 book, The
Structure of Scientific Revolutions, Thomas Kuhn used the term “paradigm” to describe the set of preconceptions that is assumed to
represent the objective reality of a particular field of science at any given time.
The classic example is the shift from the Ptolemaic paradigm that the earth was the stationary center of the universe to the Copernican view that the sun is the center of the solar system. The Copernican model isn’t perfect, but it is a far more accurate depiction of objective reality than the prior paradigm. It didn’t change any of the previous observations/subjective perceptions – the sun still “rises” in the east every morning. However, by presenting a more accurate depiction of objective reality, the Copernican model provided a far better conceptual framework within which scientists could interpret observations and solve problems.
A life sciences example is the Germ Theory of infectious diseases. Until relatively recently in human history (late 19th century), the prevailing belief was that infectious diseases were caused by a miasma that arose from bodies of water. There was a statistical correlation between unsanitary water and outbreaks of infectious diseases. Improving sanitation did reduce the risk of infectious disease. But once an individual contracted an infectious disease, only the symptoms could be treated. No medical intervention would cure the disease. However, once the Germ Theory that infectious diseases are caused by invading pathogens was accepted as objective reality, effective medical interventions became possible. Knowing the cause of a disorder allows medical technology to attack that cause instead of merely treating symptoms. As a direct result of the acceptance of the Germ Theory, medical technology has become remarkably adept at dealing with infectious diseases.
The Aging Paradigm's Misconceptions
The aging paradigm is the set of shared preconceptions that are assumed to represent the reality of aging. It’s what “everyone knows” to be true about aging. The preconceptions and hidden assumptions that make up the paradigm both reinforce and build upon one another. But since each preconception is based on the premise that all of the other preconceptions are accurate representations of objective reality, a flaw in any preconception can jeopardize the validity of the entire conceptual framework. In fact, as is discussed in the essay entitled “Misconceptions Embodied in the Aging Paradigm,” and summarized briefly below, each of the foundational preconceptions that make up the current aging paradigm – those aspects of aging that we all accept as true without questioning – are inconsistent with objective reality.
One foundational preconception of the current aging paradigm is that all phenomena associated with the term “aging” constitute a single biological trait. A critical way in which the New Paradigm introduced on this website differs from the current aging paradigm is by identifying that progressive loss of functionality/FDS has a different root cause from the cosmetic changes that are associated with advancing chronological age. They are two distinct phenomena. The cosmetic changes – graying and thinning hair, for example – are natural. FDS is a disorder.
Another fundamental preconception is that aging is irreversible. That is certainly true of chronological aging. We cannot turn back the calendar. However, since “aging” is assumed to be a monolithic trait, the corollary assumption is that all symptoms of FDS are also irreversible. But that is simply not true. Lifestyle changes don’t just slow the rate at which the symptoms of FDS worsen. Through lifestyle changes, a person of practically any age can improve the functionality of various physiological systems, thus “reversing aging.”
It has always been assumed that the progressive loss of functionality with advancing age is a genetically inherited trait simply because it is a characteristic that is observed in substantially all humans. As discussed below, that preconception is diametrically opposed to the principles of natural selection, which mandate that FDS cannot be a genetically inherited trait. The pernicious hidden assumption that underlies the aging paradigm’s misconception is that phenotype matches genotype. Physiological characteristics that are shared by substantially all members of a species are not necessarily genetically inherited traits. The New Paradigm is based on the notion that the FDS that is observed in most, but certainly not all, humans at a relatively young age is the result of environmental factors causing phenotype to vary substantially from genetic potential.
Another fundamental preconception of the current aging paradigm is that substantially all species share the same biological aging trait. But in its evolutionary environment, no mammal ever shows any signs of diminished functionality – they all die from aging-independent causes of death before they showed any signs of aging. See the essay entitled “Aging in Other Species.” Remarkably, even though a number of prominent aging theorists have acknowledged that progressive loss of functionality is a phenomenon that is unique to humans (in the evolutionary environment), none have suggested that that objective reality undercuts this preconception.
Aging theorists have always assumed that maintaining a living organism would be as easy as maintaining a machine. Components, might occasionally suffer damage due to wear and tear or entropy. So there are a number of “theories” of aging focused on identifying various types of damage that appear to be unavoidable. In reality, maintaining a complex organism is an extraordinarily complex process. As discussed in the essay entitled “Intrinsic Damage and the Human Maintenance System,” intrinsic damage is a powerful and inexorable force. By identifying various sources of unavoidable damage, these damage-based theories support that notion. Moreover, the fact that intrinsic damage is an inexorable force supports the most critical tenet of the New Paradigm — that the human maintenance system is a robust and critical biological system.
The Aging Paradigm and the Theory of Evolution
Prior to Darwin’s proposal of the theory of evolution by natural selection, there was no reason to question the universal assumption that all organisms were subject to a pro-active aging process that was designed to result in death. But Darwin recognized that the presumed existence of such a process posed a potentially fatal flaw to his new Theory of Evolution by Natural Selection. Natural selection designs organisms for optimal survival and reproductive success. Biological aging is characterized by the progressive deterioration of physiological function. How can a process that causes the progressive loss of functionality possibly increase the likelihood of survival and reproductive success?
Darwin proposed two alternative rationales to attempt to resolve that conundrum. These two rationales for how the aging paradigm can co-exist with the theory of natural selection have framed the debate ever since Darwin proposed his theory.
The first of the two rationales was an attempt to explain how the existence of a distinct physiological aging mechanism might be consistent with evolutionary principles. A process that is designed to cause death might make sense on a species wide level as opposed to the individual level. If a finite lifespan benefits a species as a whole, it would make sense for evolution to select traits that result in the death of the individual members of the species. This rationale, which is based on the notion that humans have a distinct genetically programmed biological aging process, is now commonly referred to as Programmed Aging (PA). The PA rationale is discussed in the essay entitled “Critique of the Programmed Aging Rationale,” and briefly summarized below.
The second possibility proposed by Darwin was that progressive dysfunctionality is not preprogrammed; instead it is the result of natural selection losing interest at some point. Under this rationale (sometimes referred to as Evolutionary Neglect), damage results from the accumulation of random, irreparable losses in molecular fidelity. As the result of Evolutionary Neglect, there comes a point in human development when the buildup of damage simply overwhelms whatever limited repair capabilities we have. A number of different commentators have proposed varying iterations of this rationale. Since the one thing that all of these hypotheses have in common is that they reject the notion of a distinct physiological aging mechanism per se, they are labeled Non-Programmed Aging (NPA). The NPA rationale is discussed in the essay entitled “Critique of the Non-Programmed Aging Rationale,” and briefly summarized below.
The debate between the PA proponents and the NPA proponents has never been resolved. Over the years, both sides have made excellent arguments as to why the position advocated by the other side is fatally defective. NPA proponents have suggested that “to hold to the idea that ageing is programmed, in the face of the evolutionary logic and experimental evidence to the contrary, is as unpromising a scientific stance as to continue to assert that the sun orbits the earth.” In response, PA proponents have described the NPA approach to be one of eliminating PA as an alternative, and then “devising the least implausible non-programmed theory and then constructing the least implausible interpretations of empirical evidence that support the theory.” In a universe where there are only two alternatives, attacking the other alternative rather than proving one’s own case is not an unreasonable approach. Each side has presented excellent reasons why the opposing rationale is fatally flawed, but neither has presented a convincing (or even believable) case for itself.
The PA/NPA debate is of critical importance for the following reason. Darwin knew, and every aging theorist since Darwin has also known, that the aging paradigm is diametrically opposed to the principles of natural selection. The aging paradigm and the theory of evolution can co-exist only if either the PA or NPA rationale is correct. After 160+ years of debate, it’s clear that both the PA and the NPA rationales are fatally flawed. Thus, the aging paradigm and the theory of evolution simply cannot co-exist – one of them must be wrong. The theory of evolution is the most powerful of all life sciences theories – it has been tested and validated countless times over the ages. On the other hand, the current aging paradigm is nothing more than a handful of flawed preconceptions. It is long past time for the existing aging paradigm to be replaced by a conceptual framework, such as the New Paradigm, that is based upon and wholly consistent with the theory of evolution by natural selection.
Paradigmatic Norms
Paradigms have two aspects. The first is the set of shared preconceptions that are assumed to represent objective reality. The second aspect of a paradigm refers to a framework for action that encompasses all of the values, techniques, and theories shared by the members of a scientific community. The essay entitled “Paradigmatic Norms and Paradigm Paralysis” discusses some of the norms established by the current paradigm. The validity of the norms is wholly dependent upon the validity of the underlying preconceptions of reality. The flaws in the underlying paradigm results in the misallocation of research resources.
Any normal scientist or academician is required to accept the preconceptions embodied in the aging paradigm. Since one of the hidden assumptions embodied in the paradigm is that the “aging process” is a coordinated series of steps that will inevitably result in death, the predominant metric for any experiment related to aging is longevity. Humans live too long, so other organisms are used as surrogates. However, using other organisms as surrogates is rational only if one assumes that there actually is a pro-active aging mechanism that is common to all species. But no mammal ever exhibits any symptoms of FDS during its natural lifespan. If the goal is to learn why relatively young humans suffer from FDS, it is nonsensical to use organisms that never suffer from FDS as surrogates.
Because the aging paradigm is so flawed, it has proven impossible to develop a theory that explains how and why aging occurs (the task is akin to proving why the earth is flat). Thus, unlike a scientific field such as physics, where the primary focus of a substantial number of practitioners is in improving upon and validating established theories, the vast majority of aging-related scientists are experimenters. As a result, aging science is in many ways more akin to a social science than it is to a “hard” science. Aging scientists rely heavily on statistical data with the result being that statistical correlations are conflated with cause.
Paradigm Paralysis
The essay entitled “Paradigmatic Norms and Paradigm Paralysis” also discusses, why, if the current aging paradigm is so egregiously flawed, no one has previously questioned the paradigm itself. Per Thomas Kuhn, preconceptions shared by the practitioners within a paradigm render even the possibility of alternatives counter-intuitive. To a conventional academician or scientist, questioning the paradigm is akin to questioning reality itself. Thus a fundamental characteristic of all paradigms, including the aging paradigm, is that normal scientists cannot and do not question the paradigm.
Another norm of the aging paradigm is that only practitioners within a paradigm – the normal scientists – are permitted to express any opinion about the paradigm.
The bottom line is that no normal scientist or academician would or could publish a paper challenging the current aging paradigm. And no article generated by anyone other than a normal scientist or academician will be considered for publication by any academic journal. These paradigm-protecting norms help explain why such a flawed paradigm has been able to persist for so long.
One aspect of paradigm paralysis is confirmation bias. Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms one’s preexisting beliefs. The effect is especially strong for emotionally charged issues and deeply entrenched beliefs, such as the aging paradigm.
A striking example of confirmation bias is the following. A core preconception of the aging paradigm is that biological aging is a phenomenon shared by all species. In order to rationalize that preconception, NPA proponents must argue that a fully effective maintenance system is either impossible or a trait that was not chosen by natural selection. However, for the last 75 years proponents of the NPA rationale have been citing the fact that other mammals do not evidence any signs of aging in the natural/evolutionary environment. If the members of other species have not accumulated a sufficient amount of damage to compromise functionality, then they do have fully effective maintenance systems. NPA proponents ignore their own argument that is based on the objective fact that the only species that suffers from FDS is homo sapiens.
This essay is a summary of the concepts discussed in the four essays that comprise this section of the website. Set forth below are links that will take you to each of the more detailed essays.