Naturalizing the centennial: History,memory,and the limits of human lifespans

Centennials and modern memory studies

Centennials, like centuries themselves, only gained wide notice in the early modern period (LeGoff, 2015: 3). Nevertheless, both may claim antique precedents. The civilization of ancient Rome, itself informed by Greek and Etruscan models, established the basic practice of centuriation and the tradition of welcoming new epochs, or saecula, with extraordinary rituals (Censorinus, 2007; McCluskey, 1922). In the Middle Ages, Pope Boniface VIII christianized this tradition by calling for an Anno Santo, or Holy Year, to be celebrated in Rome every 100 years (Müller, 2005; Thurston, 1900). The Jewish practice of the Jubilee, though organized around a span of 50 rather than 100 years, and rooted in a sabbatical rather than a decennial system of counting, also conveyed key themes to modern centenaries (Quinault, 1998). Indeed, in many languages, “jubilee” remains the basic term for an anniversary (Zika, 2005).

Despite these precedents, and despite scattered observances of particular centennials in the late seventeenth and early eighteenth centuries, scholars of modern centenaries agree that the nineteenth century saw the take-off of this particular class of commemorations. Roland Quinault designates the mid-to-late 1800s as the critical years for the “cult of the centenary” (Quinault, 1998). Thomas Otte, quoting a contemporary observer, deems the first two decades of the 1900’s the “age of Centenaries” (Otte, 2018). And Leerssen and Rigney (2014), in their preface to a recent study of authorial centennials in Europe, identify their timeframe as “the long century between [the earliest Shakespeare Jubilee] in 1769 and the outbreak of the First World War” (p. 4). Although we have recently witnessed the centennial of the conflict that concluded this crucial phase in the development of commemorative practices, it remains the case, as ethnographer Konrad Köstlin (2014) observes, that nineteenth-century commemorations “see[m] not far removed from today’s memorial culture.” ²

Questions of periodization pervade scholarship on centennials, but they do not exhaust it. Theorists have also analyzed the diverse forms and functions of centennial observances. A partial list of definitions and distinctions found in recent studies would include the contrast between mournful and hopeful centennials (Rigney, 2018), the shift from religious to secular jubilees (Müller, 2004, 2005), the differences between public and private commemorations (Müller, 2005), and the distinction between official and “radical” or counter-centenaries (Aalto and Dhondt, 2017; Quinault, 1998: 322).

Alongside these general definitions and distinctions, specialized literatures have grown up around the history and present forms of centennials in many particular social domains. University centennials in Europe and America have been extensively researched (Dhondt, 2013, 2014; Müller, 2004, 2005; Paletschek, 2012). Authorial centennials, as noted above, have lately become subjects of comparative historical scholarship, while they have for a long time inspired journalistic tributes (Derry, 1952; Leerssen and Rigney, 2014; Rigney, 2012). Political centennials, including the centennials of modern nations as well as the centennials of specific towns and cities, have been thoroughly documented and reviewed in official commemorative volumes and in more scientific studies (Barenscott, 2010; Boyle, 1899; Spillman, 1997; Trillo, 1996). Nor are extant researches on 100-year commemorations restricted to the analysis of texts and images. Rather, many theorists stress the ritual and performative aspects of anniversary observances (Burke, 2010; Connerton, 1989). Over the past decade, the centenary of the First World War has proved a particularly fertile field for exhibiting these different approaches to centennials (Beaumont, 2015; Briggs, 2016; Jones, 2013; Newall, 2018).

Although some scholars are interested in centennials for their own sake, others seek to connect these particular cultural formations with broader themes and concepts in the field of memory studies. Ann Rigney adopts Jan Assmann’s notion of “figures of memory” (Erinnerungsfiguren) in order to explain how the centennial of Walter Scott’s birth helped “articulate the participants’ self-image as members of different communities” within the Anglo-sphere (J. Assmann, 1995: 129; Rigney, 2012: 179). Aleida Assmann (2012) reminds us that the anniversaries of wars and massacres furnish fit occasions for “counter-memories” to arise and challenge official histories (p. 65). Recent accounts of centennial celebrations for universities and individual scientists organized by rival powers during the Second World War prove how polarizing these commemorative campaigns can be (Drüding, 2014; Gingerich, 1999).

Ongoing efforts to establish connections between historical scholarship on centennials and the interdisciplinary field of memory studies have helped illuminate political, cultural, and social dimensions of these anniversaries. For all the insights offered by such research, however, certain fundamental demographic and biological realities have been ignored. Like other investigators of the relationship between memories held “inside” and “outside the head” (Barnier and Hoskins, 2018), I believe observations from the natural sciences, particularly from physiology and cognitive psychology, should be used to supplement humanistic and social scientific perspectives on centennials. Accordingly, in the next section I will set out the basic features of a naturalistic theory of centennials. This theory promises to sharpen our understanding of the past, present, and potential future of these anniversaries.

Naturalizing the centennial

Most scholars of centennials regard their subject in the same way that the late Tony Judt saw Zeitwenden more broadly. “Precisely because it is a human invention,” Judt remarked, “the arrangement of time by decades or centuries matters in human affairs. People take turning points seriously, as a result of which those turning points acquire some significance” (Judt and Snyder, 2013: 392).

In contrast to this constructivist approach to centennials, I want to advance a naturalistic account of such commemorations. This naturalistic account is not strictly opposed to analyses grounded in the specificity of human cultures, but simply seeks to identify a common basis for highly diverse cultural formations. Specifically, the account draws on facts concerning human physiology and mnemonic capacities, derived from current scientific research, and attuned to projections concerning the future of human longevity. In this section, I will first explain what it means for a theory of human cultural phenomena to be naturalistic, and show that the natural life span theory fits this description. I will then note the key scientific findings on which the theory rests. It remains for subsequent sections of the paper to show how this theory makes sense of existing centennial practices and how it can guide reflections on possible future developments.

A theory may be called naturalistic if it seeks to explain phenomena according to known or hypothesized features of the natural world, rather than according to supernatural causes such as the intervention of divine beings (as in miracles) or according to the actions of fictitious persons (as in myths and legends). A theory that is broadly naturalistic may be more or less fundamental, depending on whether the features of the world it isolates as the explanans are general or restricted to particular environments, epochs, or populations (Mallon, 2014). Constructivist accounts of centennials (like that suggested by Judt) are, on this definition, naturalistic insofar as they assume that human cultural formations depend on natural human capacities for perception, communication, and sociability. But such accounts are not as fundamental as other possible theories, since they explain centennial practices in terms of traditions, conventions, or other social factors circulating within specific human populations, rather than more general features of human physiology and cognition.

The natural lifespan theory provides a more fundamental explanation of the diverse forms and functions of centennial observances. Like naturalizing approaches to other human phenomena, including both broad fields such as epistemology or ethics and concrete spheres of human activity such as war or economic exchange, the theory adopts an evolutionary understanding of the features of human beings and human societies that make centennials possible (Binmore, 2005; Joyce, 2007; Smith, 2009). These include, most importantly, the evolved mnemonic capacities of human beings and the evolved capacity, visible at both the level of populations and that of individuals, for human physical and cognitive systems to survive for significant but limited periods of time.

Before the early modern era, historians and philosophers speculated widely about the limits of human lifespans. The Roman (previously Etruscan) tradition of the saeculum posited a maximum human lifespan of roughly 110 years (Censorinus, 2007). The ancient historian Josephus (2003) set this number at 120 years, basing his calculation on the traditional age of Moses at the time of his demise (p. 37). The medieval Arab historian Ibn Khaldun (1989) fixed on the same limit, drawing not on the Deuteronomist but on ancient astronomical notions of the “Great Year” (p. 136). More important than the theological assumptions built into these pre-modern estimates of maximal human lifespans is the fact that no extant discussion (save perhaps that found in Pliny the Elder’s Natural History) seems to have been based on careful study of peak ages achieved within specific human populations (Beagon, 2005: 92–96).

The emergence of modern statistical investigations of maximal human lifespans corresponds closely to the rise of modern centennials. This fact does not prove, but tends to support, the natural lifespan theory. In 1693, the British astronomer and mathematician Edmund Halley published his “[E]stimate of the degrees of the mortality of mankind, drawn from curious tables of the births and funerals at the city of Breslaw [. . .]” in the Philosophical Transactions of the Royal Society (Bacaër, 2011). This was just 12 years before the English divine William Dawes commemorated the centennial of the 1605 Gunpowder Plot with a sermon on “The Continual Plots and Attempts of the Romanists Against the Establish’d Church and Government of England” (Dawes, 1706). It would be another six decades before the celebrated actor David Garrick conceived his 1769 Shakespeare Jubilee. Nevertheless, the first recognizable observances of centennials, and intimations of their future political exploitation, were present in Halley’s time.

The science of demography has advanced considerably since the late seventeenth century. There is now a well-established literature on both average and exceptional human lifespans (Haycock, 2008; Jeune and Vaupel, 1995; Maier et al., 2010). One branch of this literature seeks to pinpoint the historical emergence of centenarians. From a statistical standpoint, the probability of human populations containing some individuals aged one hundred years or more is a function of two properties of human communities: (1) average mortality levels and (2) total population size. Historical demographer John Wilmoth has argued that a global population of 100 million people, combined with an average survival rate of 14 years for adults who have reached the age of 50, would suffice to produce “an occasional centenarian” (Wilmoth, 1995). Wilmoth estimates that these two conditions may have been met as early as 5000 BCE—acknowledging, of course, the problems of verification caused by lack of clear record-keeping in antiquity (Wilmoth, 1995).

A second branch of longevity research focuses on the possibility of individual human beings achieving lifespans substantially greater than one hundred or one hundred and ten years. ³ Part of this research is forensic, aimed at confirming or disconfirming historical claims made by or about specific “super-aged” persons (Haycock, 2008: 203). Often the names and claims of these persons only survive because of the spectacular publicity surrounding their deaths, or the profits made during their lives. For example, P.T. Barnum’s earliest success as a showman came from exhibiting an enslaved woman he claimed to have been the nurse of the infant George Washington (Blake, 2006: 108). Other examples, most of them thoroughly debunked, include the Danish sailor Christian Drakenberg, the Englishman Henry Jenkins, and the Chicago entrepreneur-cum-fraud David Kennison (Kjærgaard, 1995; Haycock, 2008; Huppke, 2003).

More important for our purposes than the unmasking of past Methuselahs are scientific claims concerning an impending era of extended longevity, that is, a future period in which individuals of 120+ years of age will be roughly as numerous as individuals of 100+ years of age are today. Some reports in this area are highly sensationalistic, particularly those traceable to financiers or CEO’s touting novel procedures that promise to “disrupt” mortality (Sifferlin, 2017). But there are also legitimate scientific voices that suggest that already-existing generations may attain maximal lifespans in excess of 125 years (Thatcher, 2010: 200; Rootzén and Zholud, 2017). Although extant studies of supercentenarians do not reveal many common features, gender is one key linking factor (women outnumber men among supercentenarians), while access to modern medical procedures is another (Maier et al., 2010: 319–320). Such procedures are typically credited with making possible incremental increases in the average age achieved by individuals who surpass 100 years—with due caution counseled concerning the verification of apparent increases (Newman, 2018). But some theorists advise us to look for more radical breakthroughs, which would end speculations about a “plateau of human mortality” and usher in an era of extended longevity (Barbi et al., 2018; Rootzén and Zholud, 2017).

The maximum length of human lives is one core component of the natural lifespan theory of centennials. The range, and limits, of human mnemonic capacities is the other. We cannot say that an individual who reaches age 100 + X is capable of retaining episodic memories from any of those 100 + X years, for human memory formation does not begin at birth. As neuroscientist Daniel Schacter (2001) notes, there are no plausible instances of individuals remembering events dating from before their second birthday (pp. 126–128). Moreover, research suggests that the deepest or most vividly held memories tend to come from a fairly restricted range of years. Sociological research into the structure of human generations indicates that most vivid and enduring human memories come from a specific window of “critical years,” dating narrowly to the ages of 17–25 (Mannheim, 1998: 300) or more broadly to the ages of 10–30 (Corning and Schuman, 2015). It is important to note in this connection the general fact that certain types of experiences are effectively restricted to individuals who have reached or exceeded a certain “minimum age,” determined in each case by the particular circumstances of the societies to which they belong. These include many of the experiences, tragic or triumphant, martial or peaceful, around which contemporary centennial commemorations are organized. Finally, scientific work on memory problems arising in old age suggests that the greatest impairments may be observed in elderly individuals’ long-term, episodic memories—but these are precisely the types of memories that are bound to be most sought after during centennials (Anderson and Craik, 2000; Balota et al., 2000). ⁴ Worse, high confidence concerning false episodic memories is well attested among old and very old persons (Dahl et al., 2015; Dodson and Krueger, 2006). Taken together, these considerations suggest that even individuals who reach the (currently) extreme old age of 110 are unlikely to possess reliable episodic memories of events solemnized in centennials.

My goal in this section has been to isolate the physiological and mnemonic factors that condition modern centennial practices. These factors furnish the scientific basis for my natural lifespan theory. What I have not attempted, so far, is to show precisely how existing upper limits on the scope of individuals’ episodic memories help to explain the diverse forms and functions of centennials. Nor have I considered how a future era of extended longevity may alter existing centennial practices. The following two sections of this paper take up these tasks in turn.

The natural lifespan theory and the social functions of centennials

The explanatory power of the natural lifespan theory becomes clear when we consider the social functions currently performed by centennials. In this section, I present a novel taxonomy of those functions, focusing on the roles of centennials as (1) standards of greatness, (2) mirrors of progress, and (3) spurs to renovation. In each case, I argue, existing cognitive and physiological limits on first-personal episodic memories help make those functions possible, and help explain their social utility.

Centennials have long supplied standards of greatness. That is to say, the passage of 100 years has long been regarded as a suitable interval for assessing the value of persons, institutions, and productions. Samuel Johnson, in his Preface to Shakespeare, defends the achievements of that playwright by remarking that the Bard “has long outlived his century, the term commonly fixed as the test of literary merit” (Johnson, 1968: 61). Johnson’s precise estimate of this test of time may be based on the Roman poet Horace’s half-joking suggestion, in his Epistles, that a hundred years be fixed as the limit separating “ancient, and worthy” poets from “rank” modern writers (Ferry, 2002: 113). But Johnson also suggests a demographic basis for this interval. Once 100 years have passed,

The effects of favour and competition are at an end; the tradition of his friendships and his enmities has perished; his works [. . .] can neither indulge vanity nor gratify malignity, but are read without any other reason than the desire of pleasure, and are therefore praised only as pleasure is obtained. (Johnson, 1968: 61)

It is not only individuals whose achievements merit reassessment after 100 years. The first university centenaries, as historian Winfried Müller (2005) notes, began as Reformation-era challenges to Papal control of the calendar of Jubilees. But these institutional milestones have now become largely secular celebrations, carried out via the publication of official histories, through conferences exhibiting the school’s leadership in research, and even by means of dramatic pageants that restage the institution’s founding and anticipate its future achievements. Speeches on this last theme often make explicit their authors’ assumptions about the limits of human lifespans, insofar as speakers call attention to the fact that no attendees will live to witness the next centenary. So the president of the University of Virginia, speaking at that school’s centennial in 1921, urged his audience to imagine the “bi-centennial, the great assize of your great-grand-children.” On that “far future” day, he observed, “we shall be the past, and we shall be a worthy past in proportion as we have served the present future” (Alderman, 1921).

Besides supplying standards of greatness, centennials also function as mirrors of progress. That is to say, centennials provide fit occasions for reflecting on the advances that institutions, societies, or whole civilizations have made during discrete periods of time. A basic interest in progress and its analogue, improvement, is detectable throughout the early modern period (Slack, 2015; Spadafora, 1990; Yamamoto, 2018). But such interest increased markedly in the nineteenth century, when new technologies, new scientific theories, and new fora for exchange enhanced the “visibility of progress” (Bowler, 1990; Geddes, 1887; Spadafora, 1990). This increased interest in progress is nowhere more apparent than in the century’s centennials.

In 1888, citizens of New South Wales “pause[d] for a moment amid the turmoil and busy strife of life to look with pride upon the progress and development of the country during the past hundred years” (Melbourne Argus, 1888: 6). Sixty years earlier, residents of Baltimore celebrated their city’s centennial by contrasting its scant population during the colonial period to its current status as the home of 80,000 souls (Maryland Historical Magazine, 1929). And in the spring of 1843, American scientists and scholars gathered in Philadelphia for the centenary meeting of the American Philosophical Society. Four days of learned discussion were scheduled on such topics as “The Physical Phenomena which accompany Solar Eclipses,” “The Geology of the North-East Part of the Island of Cuba,” and “The Effects of Secluded and Gloomy Imprisonment on Individuals of the African Variety of Mankind.” Before the start of this program, Society Vice-President Robert Patterson (1843) lectured on the history of the Society, noting the humble nature of its pre-Revolutionary efforts, and observing:

How different is the state of the mechanical arts at the present time in Philadelphia; where one of the members of our Society has constructed, for a public institution, an engine which for perfection of form, of workmanship, of finish, and of operation, may challenge the world; [and] where another has made, for the new steamships constructed for our protection and defence, gigantic engines, which in ancient times would have been deemed a work to be accomplished only by Vulcan and his Cyclopes (pp. 29–30).

Implicit in each of these panegyrics to progress was the knowledge that no person with episodic memories of the conditions of life of 100 years before could emerge to recount his or her experiences for contemporary audiences. In this way, centennials differ from other major nineteenth century anniversary observances, such as Queen Victoria’s 1897 Diamond Jubilee, in which public attention centered on the ways in which the world had changed within a single person’s lifetime (MaCleod, 2010: 317).

OPEN IN VIEWER

Figure 1.

Centennial mirror. Oleographic print produced for US Centennial. Louis Kurz, Artist.

To better understand how long-standing limits to human longevity underlie this second social function of centennials, it may help to turn from textual to pictorial evidence, and to examine the “Centennial Mirror” printed in conjunction with the United States’ 1876 centennial. Produced by Austrian-born artist Louis Kurz for America’s national jubilee, this large-scale (54.5 cm x 66.5 cm) oleographic print presents 18 different views of colonial society on the eve of independence, mirrored by corresponding scenes from America’s centennial year. ⁵ In one scene on the left-hand side of the print, farmhands use flails to thresh wheat; in the corresponding scene on the right-hand side, laborers feed sheaves into a belt-driven threshing machine. Elsewhere, alterations in domestic life are emphasized: so, a young woman using a needle to embroider cloth by candlelight is paired with a girl sitting under gaslight working at what appears to be a Singer sewing machine. When considering how 1876 audiences would have “read” this complex image, we may assume that many viewers would first associate themselves with one or more of the many social roles presented on the right-hand side of the print, after which they would naturally examine the contrasting scene on the left-hand side. Kurz’s Centennial Mirror thus served as a kind of time-machine, inviting viewers to imaginatively transport themselves to the lifeworld of one hundred years before. But this whole exercise relied on the fact that viewers possessed no episodic memories of America on the eve of revolution.

If centennials in their role as mirrors of progress emphasize past societal transformations, the third key function of centennials, as spurs to renovation, focuses attention on the ways in which the world should be remade. Today we think of renovation chiefly in terms of physical alterations, and plenty of these transpire in the run-up to centennials. Buildings are repainted, streets repaved, rivers redirected. But another sense of renovation is more relevant here. In the Middle Ages, monks, saints, and clerics frequently called for spiritual renovatio, signifying by this phrase a return to the authentic message of Christ. Some churchmen went further, urging a renovatio mundi, or global spiritual rebirth. This spiritual notion of renovation underpins modern centennials, calling to mind the generations that have preceded us, whose approval we yearn for, but whose assessments of our efforts remain inscrutable.

Emerson, in his 1835 “Historical Discourse Delivered Before the Citizens of Concord [. . .] on the Second Centennial Anniversary of the Incorporation of the Town,” reminded his audience that “The planting of [Massachusetts] was the effect of religious principle. The Revolution was the fruit of another principle—the devouring thirst for justice” (Emerson, 1835: 30). A hundred years later, audiences in New Zealand were urged to “keep alive the crusading spirit of those who settled and developed this country,” and to discover, on their nation’s centenary, “the moral equivalent of the struggle and hardship which were the lot of our forefathers” (Gentry, 2015: 169). More pessimistically, in 1974 the literary critic Leo Marx concluded his lecture on “The American Revolution and the American Landscape” by remarking, “as we approach the bicentennial of the Revolution, we have an obligation to acknowledge the ways in which the republic of 1976 falls short of the revolutionary goals of 1776” (Marx, 1988). Here, a centennial acknowledgment of shortcomings serves as a spur to renewal.

In 2009, the last surviving British infantryman known to have seen combat in the First World War died after attaining the extreme old age of 111. During the final, centenarian decade of his life, Harry Patch regularly testified to his experiences on the Western Front, including the traumatic Battle of Passchaendale (Briggs, 2016). Patch’s words appeared in television specials while he was still living; a British Broadcasting Corporation (BBC) radio obituary further publicized his life just after his death (Briggs, 2016). Yet even this exceptionally long-lived veteran, fully a supercentenarian according to the established definition, did not survive to share his episodic memories during the centennial of the conflict in which he fought. Indeed, no veterans of the First World War remained to observe the various national moments of silence held in August 2014 to solemnize the start of hostilities. Nor were any in attendance during the ceremonies in Paris that commemorated the war’s conclusion. Literary scholar Marlene Briggs (2016) rightly points out that “accounts by centenarians” are of interest insofar as they “may contradict established versions” of history (p. 76). By the same token, the absence of individuals bearing those memories influences the conditions under which memory is mediated during centennials. It ensures that calls for social reform can only come from persons lacking direct experience of the events commemorated.

There is, I think, a more general lesson to be drawn from the example of Harry Patch. This is that, under existing limits to human longevity, even the longest-lived persons will possess at best fragmentary memories of events that occurred 100 years before. These will, furthermore, mainly be events to which they were subjected, rather than episodes in which they were subjects. So, memories of bombardment, forced departure, the hazards and uncertainties of refugee experience, or the loss of family members may remain alive during the centenaries of historic conflicts, since very young children are exposed to these experiences alongside adults. ⁶ But episodic memories of resistance, collaboration, or surrender are far less likely to endure until centennials. Vivid impressions of parades and pageants may linger in the minds of centenarians, but these long-lived men and women will generally lack more complex memories grounded in a broader view of events and a greater experience of life. Here, we see how an apparently straightforward, logical observation about the upper limit of human lifespans can lead to unexpected insights into the contents of today’s oldest living memories.

The span of 100 years has long been, and remains today, an effective limit on the scope of first-personal memories. This basic fact underlies the development of centennials over the past two centuries, and illuminates their social functions as standards of greatness, mirrors of progress, and spurs to renovation. What may become of centennials once this natural limit has been breached is what I want to consider in the final section of this paper.

The natural lifespan theory and the future of centennials

Demographers remain divided about the likelihood of a major extension in human longevity (Barbi et al., 2018; Newman, 2018). This debate does not bar us from considering the impact such a transformation would likely have on centennial practices. While the culture of centennials seems sure to change under conditions of extended longevity, we should not expect such anniversaries, or rather their observance, to disappear entirely. The round figure of 100 years will not lose its appeal just because a certain number of super-aged persons manages to significantly surpass this span. Indeed, the commemorative cachet of centennials might well be enhanced by the presence of persons fully able to recall the events, decisions, and conditions of 100 years prior.

My methodology for thinking about the ways in which centennials might be impacted by progressive extensions to human longevity is informed by scholarship on the transformation of birthdays, public holidays, and other festal or commemorative events in American and European culture over the last century. In this field, scholars have drawn distinctions between public (or official) and private rituals (Connerton, 1989; Etzioni, 2004; Leeds-Hurwitz, 2005), between rising and declining holidays (Dennis, 2005; Shoham, 2015), and between broadly accepted and sharply contested commemorations (Dennis, 2005; Etzioni, 2004). One point repeatedly raised by theorists in this area is that diachronic variations in commemorative or celebratory practices typically unfold over the course of decades, and are not always readily apparent to participants or contemporary observers (Pleck, 2000; Shoham, 2015). A second point, equally relevant for our reflections on the future of centennials, is that “modifications of holidays both reflect changes in values and power relations and ensconce changes in values and power” (Etzioni, 2004: 30). Already, scholars have charted the link between centennials and social power when analyzing their relationship to religious reformations and political revolutions (Müller, 2004, 2005; Quinault, 1998); We should consider, going forward, how transformations in demographic realities are and are not comparable to such institutional upheavals.

In what follows, I briefly consider three structural transformations in centennial practices that may be expected to occur under conditions of extended longevity. By “structural transformations” I mean changes that may be expected to follow more or less directly from the fact of certain individuals’ living substantially longer and consequently retaining some episodic memories for a period well over 100 years. Focusing on such structural transformations, and eschewing more tenuous conjectures, should keep us from being overwhelmed by what Stephen Jay Gould once called “the grandeur of unknowable futures” (Gould, 1997: 3). ⁷

Three structural transformations stand out as likely to occur in an era of extended longevity. First, there will be new occasions for dispute about mnemonic authority before and during centennials. Second, certain wholly new opportunities for centennial commemoration will emerge—particularly within the private sphere of family life. Finally, and paradoxically, the intrusion of living memory into public centennial observances may actually reinforce existing gaps in public memory, unless and until contested by novel forms of memory activism.

The mnemonic authority of super-aged persons will no doubt be substantial during the centenaries of events they lived through, just as the testimony of principal actors carries weight in golden jubilees today. It will not, however, go unchallenged. One challenge, familiar from historiographical work on Zeitgeschichte, will come from professional historians, who may claim a more objective, a more capacious, or a more carefully sourced view of past events than that enjoyed by eyewitnesses. Both professional and amateur or local historians are, after all, regularly consulted during modern centennials. These scholars will surely seek to amend at least some of the episodic memories articulated by super-aged persons at future commemorations, even while maintaining respect for their honored status. Here, we see one way in which “values and power,” specifically epistemic power, may be implicated by demographic transformations

Besides competition from academic historians, two further challenges to the episodic memories of super-aged persons are worth mentioning. One comes from the neuroscience of memory itself, already briefly discussed above, where scholars identify several “sins of memory” that attach to the mnemonic capacities of elderly persons and to the contents of memories formed in extreme youth (Schacter, 2001). These scientific observations will doubtless affect assessments of the credibility of centenarians’ reported memories. One model for such assessments come from the skeptical view that many scholars take of eyewitness testimony from elderly persons in courtroom settings (Dahl et al., 2015; Dodson and Krueger, 2006). Although such academic critiques, as well as lay attitudes, may shade uncomfortably toward ageism (Mueller-Johnson et al., 2007), and although testimony at public commemorations does not usually have the same stakes as courtroom testimony, such age-related doubts may still work to reduce the mnemonic authority of super-aged persons.

A further challenge, of a fundamentally different kind, stems from the increasing technological mediation of memory. Augmented and virtual reality capacities, which today remain in their infancy, will soon alter the ways in which individuals and groups share their experiences with diverse audiences. Although it is difficult to speak precisely on this point, these technologies seem likely to transform centennial practices, making possible new, immersive versions of the old “Centennial Mirror.” ⁸ When high-tech simulations allow centennial audiences to achieve their own episodic “memories” of past events, the testimonial claims of actual eyewitnesses to those events will necessarily be received differently. This trend toward technologically mediated encounters with major events of the past resembles in some ways the consumerist, entertainment-driven transformations in other kinds of holidays and observances, such as children’s birthdays, traced by scholars over the past century (Etzioni, 2004; Pleck, 2000).

Moving to a second structural transformation, we should expect that some of the most notable developments in centennial practices under conditions of extended longevity will occur in the realm of private, rather than public, remembrance. There is little reason to think that fundamentally new categories of public events or actions will come to be seen as meriting official commemoration merely because of a gradual extension in the maximal lifespans of individual humans. There are, by contrast, several kinds of private, familial milestones that will first become possible objects for celebration in this scenario. Two of the most important, judging on the basis of present-day memorial practices, are hundredth wedding anniversaries and the one-hundredth birthdays of children who retain at least one living parent.

The odds of married partners both reaching the age of 115 (which I assume as an absolute minimum age for a hundredth wedding anniversary) are vastly smaller than the odds of any particular individual reaching his or her 115th birthday. For several decades in the late-twentieth century, the Metropolitan Life Insurance Company calculated the likelihood of newly married couples reaching their fiftieth wedding anniversaries (Kranczer, 1997). The very possibility of such calculations depends on demographic data that do not exist for the scenario I am considering. Leaving aside the statistical likelihood of such private anniversaries, we may consider what cultural forms they will assume if and when they first occur. Here the rise of familial celebrations for an increasing number of intervals in wedded life, from 5th to 80th, over recent decades is instructive (Köstlin, 2014: 11; Leeds-Hurwitz, 2005). The first acknowledged one hundredth wedding anniversary would likely garner extraordinary media attention, arranged by consultation with the children, grandchildren, or even great grandchildren of the spouses involved. Such coverage would likely be highly moralized, proclaiming that such an anniversary proves the capacity for married couples to survive a full century of fortune’s reverses. Contrasts drawn between the marriage customs of the distant past and the present day would be reinforced by first-personal testimony concerning the wedding rites, the emotions of the day, and so forth. But should such events become relatively common within particular societies, this public attention is likely to recede, reappearing again only when particularly prominent couples, already well-known as public figures, are involved.

Although there are a number of confirmed supercentenarians whose children subsequently became centenarians themselves, there has not, to my knowledge, been a case of a child celebrating a hundredth birthday while at least one of his or her parents was still living. The first such event to be identified in an era of extended longevity might attract a similar amount of media coverage to the first hundredth wedding anniversary, though in this case the initiative would likely have to come from a grandchild (or great grandchild) of the oldest party. What chiefly distinguishes such an event from a hundredth wedding anniversary, however, is that the former can plausibly be interpreted as an extension to a long series of anniversaries marking a specific rite of passage, and at the same time marking a recommitment to a voluntarily created and maintained relationship (Leeds-Hurwitz, 2005; Shoham, 2015). The latter is better described as marking the exceptional longevity of two human beings whose relationship is genetic, not volitional, and therefore unlikely to require recommitment. ⁹

The third, and perhaps most surprising, structural transformation to be expected in an era of extended longevity is not so much a departure from current trends and tensions as a deepening of both. Put briefly, the progressive intrusion of living, episodic memories into centennial observances seems likely to reinforce, at least initially, existing gaps in public memory. The reasons for this are multiple, but complementary. In the first place, just as current distributions of maximum lifespans are not equal across all social groups, but vary with sex, race, ethnicity, nationality, occupation, and many other demographic factors, so future cohorts of supercentenarians will not perfectly represent human populations as a whole. This is already the case with present-day supercentenarians in one regard, since “almost all are women” (Maier et al., 2010: v). But persistent differences in the quality of birth-records in developed and developing nations also suggest that the validation of claims to exceptional longevity will be easier for individuals born in the former than the latter, and this may also lead to disparities in perceived mnemonic authority. The result is that “living memories” will be more readily available for some historical actions or events than others, with the differences reflecting geography, the structure of social roles, and other intangible social and political factors.

The risk of mnemonic omission looms larger when we consider that many of the events solemnized in modern centennials are high-mortality events, that is, events during which a substantial number of witnesses lost their lives or sustained serious injuries. Such events encompass both natural disasters (floods and earthquakes) and human catastrophes (epidemics, wars and massacres). The sites of such events today attract large numbers of visitors, and there is no reason to think that this trend toward “death tourism” will end before the great human disasters of the mid-twentieth-century reach their centenaries (Sharpley and Stone, 2009; Sion, 2014). But there is reason to question whether the progressive extension of lifespans will proceed rapidly enough to allow any survivors of these catastrophes to give centennial testimony. In the face of such uncertainties, emerging forms of “postmemory,” including practices of vicarious testimony by second- and third-generation descendants of Holocaust survivors, as well as technologically advanced efforts to facilitate life-like interactions with departed witnesses to past traumas, will likely proliferate as these centennials approach (Hirsch, 2012; Traum et al., 2015). Though controversial, such practices belong to a broader landscape of memory activism which will not become obsolete under conditions of extended longevity, but rather all the more urgent. As with changes in public holidays, the success or failure of such activism may only become evident over a period of decades, as the new culture of memory that distinguishes our prospective age of extended longevity emerges.

Conclusion

In this paper, I have offered a naturalistic theory of centennials. I have shown that this theory helps explain existing centennial practices and suggested that it should orient our reflections on how such practices could change in an era of extended longevity. The several functions of centennials as standards of greatness, mirrors of progress, and spurs to renovation need not vanish once scattered eyewitnesses survive to testify to such milestones. Rather than resolving tensions between episodic or experiential and collective or constructed memories, competition between these modes of memory might easily increase under conditions of extended longevity.

Assessing prospective developments in cultural domains as complex as the marking of time and the observance of anniversaries is a fraught business. Past efforts in this direction, particularly those occasioned by the turn of the millennium, read like unscientific conjectures today (Johnston, 1991). In view of this, it is tempting to conclude that centennials, like millennia themselves, are arbitrary, mere artifacts of a particular system of counting (Demantowski, 2014; Gould, 1997). Naturalizing the centennial provides us with a compelling alternative to this skeptical conclusion. It equally encourages further reflection on the meaning of this major mode of modern memory.