The Supposed Lack of Evidence

Costanza and Finkelstein argue that there is insufficient evidence of generationally based differences in work-based outcomes. This is a very serious claim for which they provide limited support. Recent systematic and critical reviews of the research (Lyons & Kuron, Reference Lyons and Kuron2014; Parry & Urwin, Reference Parry and Urwin2011; Twenge, Reference Twenge2010) have documented a growing body of evidence concerning intergenerational differences in various work-based variables, including personality, work values, work–life balance, leadership styles and preferences, and career experiences (cf. Lyons & Kuron, Reference Lyons and Kuron2014). Recent research has also documented evidence of perceived intergenerational differences in work values among managers and employees, which are related to but different from actual observed intergenerational differences (Foster, Reference Foster2013; Lester, Standifer, Schultz, & Windsor, Reference Lester, Standifer, Schultz and Windsor2012). However, as might be expected with a nascent field of inquiry, the existing evidence is difficult to aggregate and compare because it relies on different contexts (e.g., industry and country), different methodologies, different conceptualizations and operationalizations of generation, and different data collection periods (Lyons & Kuron, Reference Lyons and Kuron2014; Parry & Urwin, Reference Parry and Urwin2011).

Costanza and Finkelstein further argue that the effect size of intergenerational differences is small, suggesting that the differences lack practical significance. Twenge (Reference Twenge2010) has noted that the effect sizes observed in generational research are often moderate and are sometimes large in size. She argued that there is no agreement on what a practically significant effect size should be in the context of generational comparisons, resulting in an expectation of effect sizes that are larger than are feasible for a variable as complex as generation. Twenge further showed that some researchers tend to dismiss moderate-sized generational effects as trivial even though they are similar in magnitude to those observed for gender and other individual difference variables (Twenge, Reference Twenge2010).

It is our contention that there is abundant evidence that intergenerational differences exist both in objective and perceptual terms. The problem is not a lack of evidence so much as a lack of comparability between the growing body of evidence that exists. Lyons and Kuron (Reference Lyons and Kuron2014) have advocated for a more detailed description of sample demographics and contextual factors, as well as consistent reporting of effect sizes in order to bring clarity and consistency to the research and to facilitate meta-analyses.

The Age–Period–Cohort Confound

Like many previous commentators (e.g., Kelan, Reference Kelan2014; Parry & Urwin, Reference Parry and Urwin2011; Rhodes, Reference Rhodes1983; Ryder, Reference Ryder1965), Costanza and Finkelstein have argued that the construct of generation faces a validity challenge because generational effects are inherently confounded with age (i.e., life cycle) and historical period effects. For decades, psychologists have sought to disentangle these confounded effects through increasingly elaborate research designs and statistical processes. A number of recent studies have employed longitudinal research such as time-lag studies (Twenge et al., Reference Twenge, Campbell, Hoffman and Lance2010), cross-temporal meta-analyses (Twenge & Campbell, Reference Twenge and Campbell2001), sequential longitudinal designs (Krahn & Galambos, Reference Krahn and Galambos2014), and sample reconstructions (Cogin, Reference Cogin2012; Smola & Sutton, Reference Smola and Sutton2002), which offer better insights into generational change over time. These studies have documented intergenerational differences that cannot be attributed solely to age. However, none of these approaches adequately controls for historical period, because we cannot step “outside of history” to observe the variance that a historical period creates. Readers interested in a fuller consideration of these issues should refer to Parry's (Reference Parry2014) edited volume, which offers many useful perspectives on the matter.

We refer to the foundational theory of generations, which does not suppose that disentangling these confounding effects is necessary or advantageous to our understanding of the phenomenon. Karl Mannheim (Reference Mannheim1952), the father of modern generational theory, argued that for generation to be a useful construct above and beyond age and period, we must view it as a gestalt—as a fundamental confluence of biology and history. Viewed from this perspective, we should always examine the joint influences of age within cohort within period. There is significant recent evidence that suggests that the human life cycle is not static but is dynamic as social and historical forces continue to evolve. For example, Arnett (Reference Arnett2000) has documented a prolonged period of entry into adulthood in recent decades, which he has termed “emergent adulthood.” Census statistics and large-scale survey data from North America confirm Arnett's hypothesis; people are spending more time in education, are living with their parents later into adulthood, and are getting married and bearing children later in life than in the past (Statistics Canada, 2011; Taylor, Reference Taylor2014; U.S. Census Bureau, 2014). Curiously, even seemingly fixed biological markers, such as the age of menarche (one's first menstrual cycle) appear to be dynamic over time (Okasha, McCarron, Smith, & McEwen, Reference Okasha, McCarron, Smith and McEwen2001).This suggests that although age is an important factor shaping individual differences, it only has meaning relative to the experiences of one's cohort and the historical events that intersect with each stage of the life cycle. Likewise, historic events provide a context that shapes individuals, but their influence is moderated by the age at which one encounters these events and the nature of the cohort-peers with whom one contemporaneously experiences them. Again, we see the inherent confluence of these three factors not to be a failure of the generational construct but rather to be the purpose for it.

The Supposed Lack of Theory

Costanza and Finkelstein argue that there is “no sufficient explanation for why [intergenerational] differences should even exist” (p. 3), implying that there has been no theory to guide extant research. They conclude by stating,

The good news is that they do not need to wait for the development of such theory; it already exists. There is a rich body of theory concerning generations as a social phenomenon (e.g., Alwin & McCammon, Reference Alwin and McCammon2007; Eyerman & Turner, Reference Eyerman and Turner1998; Mannheim, Reference Mannheim1952). Beyond the broad sociological theories, Joshi and colleagues (Dencker, Joshi, & Martocchio, Reference Dencker, Joshi and Martocchio2008; Joshi, Dencker, & Franz, Reference Joshi, Dencker and Franz2011; Joshi, Dencker, Franz, & Martocchio, Reference Joshi, Dencker, Franz and Martocchio2010) have proposed a theory (and definitions) of generational cohorts and how they influence interactions and behaviors within workplaces. This theory largely draws on (and highlights the applicability to generations of) social identity and self-categorization theories (Ashforth & Mael, Reference Ashforth and Mael1989). Other theories from a variety of disciplines have also been applied to intergenerational phenomena. For example, Urick (Reference Urick2014) applied dramaturgical theory (Goffman, Reference Goffman1959) to theorize when and how individuals choose to conform (or not) to stereotypes of generational categories.

Unfortunately, a great many researchers have neglected to draw on such theoretical contributions, relying instead on the rather weak justification of testing popular caricatures or depictions of the generations (Lyons & Kuron, Reference Lyons and Kuron2014; Twenge, Reference Twenge2010). We do not endeavor in this brief commentary to review the body of theory supporting generations as a genuine and important social phenomenon. Instead, we refer readers to the works cited above and to the reviews by Gilleard (Reference Gilleard2004), Kelan (Reference Kelan2014), and Lyons and Kuron (Reference Lyons and Kuron2014), which discuss various theoretical contributions in greater detail. Efforts to integrate and expand intergenerational theory are ongoing, several of which are discussed below.

The Problem of Demographic Determinism

A key tenet of Costanza and Finkelstein's argument against generational differences as a legitimate workplace phenomenon is the tendency to apply stereotypes to all members of a birth cohort. They cite examples of stereotypes of four different generational cohorts gleaned from media and popular press that are often used as supporting evidence in academic work on the topic. The crux of Costanza and Finkelstein's argument is that, because the influences that are purported to shape a generation might not apply to “any one member” (p. 7) of a generation, the construct of generation is invalid. We would argue that this logic relies on an expectation of demographic determinism—that demographics such as birth year determine the future for which individuals are destined—which does not reflect the nuances of generational theory.

Mannheim's (Reference Mannheim1952) seminal theoretical work expressly states that generations are not monolithic. A generation, from this broader theoretical perspective, is more than simply a cohort of people born in the historical period. It is a collective consciousness that emerges within a cohort with which individuals will identify to varying degrees (Alwin & McCammon, Reference Alwin and McCammon2007). Mannheim (Reference Mannheim1952) posited that each generation comprises subunits that are supportive of, opposed to, and ambivalent to the broader generational consciousness. It is one's identification with one of these generational units that defines one's place within the larger generation. It is possible that the opposing unit within one generation holds values similar to the “leading” unit of the preceding generation. The similarity of these individuals’ values would suggest between-generation invariance, which is often taken to be proof of the nonexistence of generations. However, their similarities belie important differences in their relative positions within their respective generations. Although one might be labeled conservative or traditionalist within the context of his or her generation, the other might be labeled progressive or liberal within his or her generation. Thus, within-cohort variance does not disprove the existence of generations; it is an interesting empirical feature of generations that helps us to delineate patterns of thought and action within the generation.

Surely we would not apply the same logic to other demographic variables. For instance, should we dismiss gender as a demographic basis for individual differences because we cannot show that all women are exposed to the exact same environmental and biological influences? Our understanding of gender and other demographic variables such as ethnicity and socioeconomic status has evolved over time to become more nuanced and complete. Our understanding of generation must also undergo such examination and refinement. Thus, although we concur with Costanza and Finkelstein that we should not presume that birth cohort imbues individuals with homogeneous values, attitudes, or behaviors, we accept this as a fundamental tenet of Mannheim's generational theory, not a failure of it. The problem, therefore, lies with the assumptions of cohort-focused research, not with the construct of generation itself.

Generations as Social Identities: One Person's Stereotypes Are Another Person's Prototypes

Costanza and Finkelstein make the apt point that the use of stereotypes as the basis for management and HR decision making is a dubious practice that should be avoided. They give examples from the media and popular press that make exaggerated claims and unwarranted extrapolations based on stereotypes and advise that this is inappropriate. We have no cause to argue with this position, which we believe most academics would view to be a truism. We certainly echo the voices who have advocated for informed, evidence-based decision making rather than reliance on glaring generalizations and unsubstantiated news articles and popular press books (e.g., Latham, Reference Latham2009). However, we wish to note that stereotypes are key to understanding perceptions and identity in organizations. If we substitute the pejorative term stereotype with the more neutral term prototype, we can link our understanding of generations to the substantial body of work concerning social identity and social categorization theory (Ashforth & Mael, Reference Ashforth and Mael1989) as noted earlier. This theory tells us that the prototypes that we carry in our minds are an important sense-making tool. We agree that such heuristics are appealing because they are quick and easy, but they are also part of the innate process of defining social identity (Ashforth & Mael, Reference Ashforth and Mael1989). Joshi and colleagues (Reference Joshi, Dencker, Franz and Martocchio2010, Reference Joshi, Dencker and Franz2011) have considered this as part of their theoretical contribution to understanding generations in the workplace.

We unreservedly concur with Costanza and Finkelstein that managers would be ill advised to revamp their management styles and HR systems on the basis of generational caricatures and support the notion of celebrating diversity and inclusiveness on various bases, including generation. However, we also contend that managers can gain a deeper understanding of the identity patterns of their employees by listening for evidence of generation talk within employee discourse. We take issue with the suggestion that managers and employees are mere parrots of the stereotypes purveyed by the media. Those stereotypes resonate because they “fit” as explanations of the workplace dynamics they are encountering. For example, generational labels are known by managers and employees, and they impact behaviors and interactions (Urick & Hollensbe, Reference Urick, Hollensbe and Parry2014). It is quite possible in many situations that there are deeper bases for social identity and sense making that should be explored. An awareness of the use of generational prototypes as sense-making tools can help managers to push for the deeper connections that might bridge the gap between superficial generational differences.

Where Do We Go From Here? Future Directions for Research

A number of commentators have previously noted the empirical challenges inherent in studying generations and have offered guidance as to how the research might move forward (e.g., Lyons & Kuron, Reference Lyons and Kuron2014; Parry, Reference Parry2014; Parry & Urwin, Reference Parry and Urwin2011). Costanza and Finkelstein seem to be suggesting that we abandon generational research altogether. Giving up on generational research now would be a mistake. Costanza and Finkelstein argue that all of the important individual difference variables and their relationships to work outcomes have already been investigated, so a generational perspective adds nothing to our existing knowledge. The same argument could have been made against any of the other individual difference variables for which there is now an amassed body of research. Every field of empirical research starts somewhere. As Colquitt and Zapata-Phelan (Reference Colquitt and Zapata-Phelan2007) have noted, research in a new area tends to begin with description, which leads to theory testing and refinement. What is needed at this juncture is not an end to generational research but a change in its focus. Rather than asking the same questions in different ways, it is time to ask different questions.

We reiterate the recommendations of Lyons and Kuron (Reference Lyons and Kuron2014) and Urick (Reference Urick2012) that future research on generations should employ multiple and mixed methods. Specifically, what is needed now is greater understanding of generations from a qualitative perspective, which will help us better understand the ways that generation shapes our perceptions, our discourse, and our identities. It will also give us a clearer sense of how well the generational cohort approach, embodied in the use of birth years as demographic categories, actually predicts the generational identification. Research has already begun to move in this direction. Foster (Reference Foster2013) has applied discursive theory to generational phenomena to understand how generations are talked about in relation to work. Roberto and Biggan (Reference Roberto, Biggan and Parry2014) used a mixed-method quantitative and qualitative approach to examine people's identification with generational categories and their tendency to stereotype generational outgroups. Schuman and Scott (Reference Schuman and Scott1989) have investigated the role of collective memories as the common bond that bonds members of a generation. All of these promising avenues for research serve to enlighten and further our understanding of generation as a phenomenon far richer and more complex than mere demographic categorization.

Costanza and Finkelstein argue that researchers and managers should abandon the quest for evidence of generational differences and focus instead on “real” differences that have been documented more convincingly in previous research. However, the fact that a phenomena has not yet been adequately measured does not necessarily imply that it is “unreal.” Michell (Reference Michell1997) argues that legitimate quantitative science involves two tasks: (a) the scientific task of showing that a phenomenon is quantitative and (b) the instrumental task of operationalizing the phenomenon for the purpose of accurate measurement. Michell (Reference Michell1997) also argues that impatient researchers often ignore the difficult task of proving that a complex phenomenon can be quantified and skip straight to the task of tinkering with measurement issues. The generational research appears to be a prime example of this phenomenon. Researchers have rushed to provide “proof (or disproof) of concept,” according to their particular bias, by merely measuring mean differences between people falling within various ranges of birth years. This approach presumes that (a) mean scores based on birth year are a reasonable measure of the attitudes or values of a generation and, more important, (b) generation is a quantifiable phenomenon to begin with (Alwin & McCammon, Reference Alwin and McCammon2007). Generations, as theorized by Mannheim (Reference Mannheim1952), are complex and dynamic multilevel systems of influences that may be difficult to quantify. A generation might be an example of a complex emergent phenomenon, in which novel and coherent structures, patterns, and properties arise and are perceptible at the macro level through self-organization in a multifaceted system of factors at the micro level (Goldstein, Reference Goldstein1999). If such a system is quantifiable, it certainly defies simple measurement.

Although we do not disagree that other sources of individual difference are important sources of understanding diversity and inclusion, this does not preclude seeking a deeper understanding of generations as interpersonal workplace phenomena. Employees’ and managers’ perceptions regarding generational differences, whether accurate or not, have real implications for practice and are worthy of study (Foster, Reference Foster2013; Lester et al., Reference Lester, Standifer, Schultz and Windsor2012). Costanza and Finkelstein agree but caution that the reality of these perceptions is potentially harmful to good management. It is our opinion that a better understanding of perceptions of intergenerational differences and their sources is an important element of diversity management and offers excellent potential for learning.