The notion of a “Millennial” generation, much like a “Generation X” or the “Baby Boom” generation, with a strong coherence in terms of values and norms that differ from previous cohorts, has been of dependable interest in the popular press. However, given what we know regarding the proportion of trait expression due to sources largely immune to cohort effects (e.g., large genetic contributions), how difficult it is for us to systematically influence their expression (e.g., small long-term parental effects), and the massive variation within groups, the meta-analytic work of Costanza, Fraser, Badger, Severt, and Gade (Reference Costanza, Fraser, Badger, Severt and Gade2012) underscores what should already be known from first principles; generation or cohorts are inevitably a poor predictor of anything. The literature on ingroup/outgroup bias (Hogg & Abrams, Reference Hogg, Abrams, Abrams and Hogg1990), stereotype formation (Mackie, Hamilton, Susskind, & Rosselli, Reference Mackie, Hamilton, Susskind, Rosselli, Macrae, Stangor and Hewstone1996), and reconstructive memory issues (Schacter, Reference Schacter1999) provides ample underlying evidence for how these generational overgeneralizations form.

As a starting point, we note the persistence of reported generational differences across many generations. Costanza and Finkelstein (Reference Costanza and Finkelstein2015) note that Hesiod wrote disparagingly about “the youth of today” in 800 BCE. In 6th century BCE China, both Laozi and Kong Fuzi noted that a form of proper conduct in ancient time had been lost to the young. Moving forward, we have Plato in Greece complaining of the neglect of proper conduct in noting that several questions are no longer answered by the youth of today: “When the young are to be silent before their elders; how they are to show respect to them by standing and making them sit; what honor is due to parents?” Moving forward another 400 years, we have Seneca in Rome noting, “Our young men have grown slothful. They sing and dance and grow effeminate and curl their hair and learn womanish tricks of speech.” Jumping a millennium we have “The young people of today think of nothing but themselves. They have no reverence for their parents or old age. They are impatient of all restraint,” attributed to Peter the Hermit. Similar references are readily available for most time periods and a variety of cultures, with a variety of attributions for forms of “the world is going to hell and children are no longer respectful to their elders” (O'Toole, Reference O'Toole2012). In all of these cases, the young are seen as coddled, undisciplined, and lacking respect for tradition. Given the durability of this narrative across time and culture, the generational myth seems to have strong underlying appeal. We agree with Costanza and Finkelstein that this generational stereotype is strong, but the question remains: Why is it so durable?

Stereotyping, as a cognitive process, has been well documented in the psychological literature (Mackie et al., Reference Mackie, Hamilton, Susskind, Rosselli, Macrae, Stangor and Hewstone1996) and does not need to be discussed at length here. Human beings are highly prone to overgeneralize about groups, seek out evidence consistent with our stereotypes, and brush off inconsistent information. Another related process is outgroup biases (Hogg & Abrams, Reference Hogg, Abrams, Abrams and Hogg1990), in which we assume that individuals who are different from us are highly similar to one another and in some way inferior to our own group. Finally, availability and representativeness heuristics come into play in stereotyping (Tversky & Kahneman, Reference Tversky and Kahneman1974) and generational perceptions in particular. When discussing a specific generation, we tend to rely on the information that is most likely to be publicized. Novelty is prized in the press, as few would purchase a news source noting that things haven't changed much over time. Instead, it is more salient for readers and more likely to generate interest to note that there have been changes in attitudes and behavior in response to changing conditions.

Availability is also influenced by access to the press and links between the members of the press and their social and economic base. Journalists are very disproportionately educated, White men from comparatively wealthy backgrounds (Weaver, Beam, Brownlee, Voakes, & Wilhoit, Reference Weaver, Beam, Brownlee, Voakes and Wilhoit2007), and so they likely report on the trends that affect these groups; the business press especially is made up of such individuals. The trends that affect lower income individuals are reported less frequently. In reporting on the United States in the 1960s, for example, the portrayal of rebellious college students understated the large contingent of working-class individuals who served proudly in Vietnam and helped to found the contemporary conservative movement (Brennan, Reference Brennan1995). Today's writing regarding “helicopter parents,” constant affirmation, and access to sophisticated electronics and social media bypasses a huge cohort of lower income individuals who are more likely than ever to be raised in single-parent homes with few opportunities for encouragement or expectation of upward mobility and less time for the frivolous social media activity that is said to characterize this generation (Bianchi, Reference Bianchi2011).

Memory distortions are one powerful source of stereotyping for cohorts, as memory is now known to be very malleable (Schacter, Reference Schacter1999). As Walker, Skowronski, and Thompson (Reference Walker, Skowronski and Thompson2003) review, autobiographical memory typically favors pleasant over unpleasant memories, with bad memories fading with time, a notable exception to bad stimuli providing stronger reactions than good. This makes our recollection of our past biased toward the idyllic and makes us very susceptible to the adage “Things were better then.” Combined with the “reminiscence bump” (Glück & Bluck, Reference Glück and Bluck2007), where people recall more events from their teenager and early adulthood years, which again tend to be recollected positively, the past will be a golden age for almost all of us, given time. Consequently, the generational myth is due to the same source that made Pinker's (Reference Pinker2011) observation surprising: violence has substantively declined century over the 20th century, including a precipitous drop in assault and murder in the United States since a peak in the early 1990s. This also explains why comments criticizing today's youth tend to be associated with that of society in general (e.g., “the world is going to hell”). We think the past was better than it actually was because we remember it this way. This tendency is exacerbated by the “lazy media” to which Costanza and Finkelstein alluded. Articles and books pander to this stereotype, as it is a ready-made meme we easily ingest. To believe that this observation is itself new, though, would be another myth. Samuel Johnson wrote about largely this in 1750, noting that “one generation is always the scorn and wonder of the other.”

Stereotypes and outgroup biases can also arise due to partial truths coupled with misattribution of cause. When we are young, we may well exemplify many of the perpetual criticisms made of the “youth of today.” To properly separate cohort effects from maturation, a meta-analytic longitudinal review by Roberts, Walton, and Viechtbauer (Reference Roberts, Walton and Viechtbauer2006) is particularly informative. They examined how personality changes over the lifetime, identifying several strong maturation effects and a few very weak cohort effects. Emotional stability increases significantly with age, so the young are indeed more volatile in their moods. Conscientiousness, a trait that can be linked to the issues of respect for order and authority so bemoaned as lacking in the “youth of today” over time, also increases over the course of a life time. Sociability declines from adolescence until the age of 30, then holds steady until the age of 65 or so, and then declines some more. Social dominance, such as self-confidence and independence, increases until about the age of 40 and then holds steady. Thus, younger people are more interested in their peers and keeping up with trends and may be less sure of themselves. Openness to experience remains stable until one's 60s and then declines. The elderly are indeed slightly more set in their ways. As we grow older, we become more agreeable (that is, community minded) and more emotionally stable (that is able to deal with life's vicissitudes). In short, the young tend to be lazier, more energetic, more exploratory, more selfish, and more dramatic than are their elders. Of course, these are only group trends and do not reflect the huge variation within each group. There are multitudes of hardworking and steadfast youths as well as countless shiftless and histrionic elderly.

Cohort-like effects can appear as a result of changing economic conditions encountered in youth and can extend over sufficient duration that they can be confused with a cohort effect. For example, a generation may enter the workforce at a particularly propitious time, where multiple job offers and good prospects are the norm. This may give rise to a heightened sense of entitlement, which is then attributed as an enduring characteristic of the generation, especially by those who are older and who have more modest memories of their initial workforce experience. However, once the economic boom passes, so soon does the seeming attitude. Consequently, there is no cohort effect; it is merely a temporary reaction to a changing economy. Tulgan (Reference Tulgan2004) provides a particular relevant business example of this. If companies no longer offer lifetime employment, it is irrational for those who are entering the job market to expect job security. Anyone, given the constant threat of layoffs, would reconfigure their career path to be more transitory. Those older, with their past experiences of employment stability, may adapt somewhat more slowly to new economic realities, but this should hardly prove an enduring characteristic. What may be attributed to a cohort effect is simply a minor delay in learning curves. As Tulgan points out, “In just 10 years, workers of all ages have lost confidence in the old-fashioned career path and traditional norms of success” (p. 24). Similarly, Ferres, Travaglione, and Firns (Reference Ferres, Travaglione and Firns2003) found little support that Generational Xers are lest trustful regarding their employer: “Unexpected results indicated that generational category did not impact on respondents’ affective bond with their organisation, or their levels of trust at work” (p. 327).

Aside from what Costanza and Finkelstein consider, there are plenty of alternative supporting examples, such as Rotolo and Wilson's (Reference Rotolo and Wilson2004) longitudinal examination of volunteerism. They focus on the Civic or Greatest Generation, whose depression and wartime experiences apparently prepared them for self-sacrifice, a value that subsequently generations were criticized as not adopting. To study this, they looked at volunteer patterns for middle-aged women in 1974 and 1991. They also controlled for a variety of situational variables, including education, work hours, weeks worked, occupational status, marital status, and parental status. As expected, these situational variables all predicted volunteering and, after controlling for them, there was no generation effect. Simply put, there was no cohort influence on volunteering; rather, it is simply affected by maturation and the different responsibilities and constraints of life stage.

Still, this doesn't mean there isn't a pressing cohort problem. Indeed, there is an upcoming generation-specific conflict for many high and upper-middle income countries that will definitely have a tremendous economic impact and is unambiguously observed. As Lee, Mason, and Members of the NTA Network (Reference Lee and Mason2014) review in Science, replacement fertility rate is 2.1 children per mother, and as it drops below 1.6 kids, it starts to become increasingly difficult to sustain government programs and standards of living. Multiple countries around the world, such as Germany, Spain, Thailand, and Taiwan, have birth rates so low that they are effectively imploding. What's the problem with the youth of today? It is that often there isn't enough of them.