A briefing paper prepared for the Council on Contemporary Families Online Symposium on Gender and Millennials, originally released March 31, 2017.

“Millennials” is a term coined by Neil Howe and William Strauss to refer to the cohort of young people who were entering adulthood at the beginning of the 21st Century. In two best-selling books, these authors described youths born in the 1980s and 1990s as qualitatively different from – and superior to – the preceding Generation X. In fact, in their second book about Millennials, Howe and Straus equated Millennials with the GI generation—also known as the Greatest Generation–labeling both “hero” generations. Millennials, they opined, had seven core traits. Treated as “special” and “sheltered” while growing up, they became confident, team-oriented, conventional, pressured, and achieving.

Strauss and Howe initially drew the Millennial cohort’s boundaries as the two decades of births spanning from 1982 through the 1990s, but the early boundary has been pushed back to the late 1970s by some writers, and Howe and Strauss later extended it to people born up through 2004.

In other words, the Millennial birth cohort has become larger and larger over time and so have the adjectives used to describe them. A recent Google search produced nearly 40 million references to Millennials, but even the most casual reading of the literature quickly reveals just how promiscuous the term has become and how contradictory are the generalizations made about what they are like and how they will drive social and political change.

What is a cohort, anyway? Demographers and sociologists make an important conceptual distinction between age cohorts and age categories. There is a simple way of understanding the difference: Birth cohorts have a life span while age categories are a slice of the population at a point in time. People move out of age groups but they remain in their birth cohort.

Karl Mannheim, the eminent political sociologist, conjectured that a birth cohort shares a specific historical experience and may form a common identity or consciousness in early adulthood as age peers try to make sense of or adapt to critical political, economic, and social events. This idea was picked up and widely adopted by social scientists in the middle of the last century as the Baby Boom generation emerged.

But Howe and Strauss, and many pundits since, have gone a step further, attributing to each particular age group a unique “personality,” worldview, and set of attitudes or psychological characteristics that is distinct from previous cohorts and common to most members. While this makes for good copy, the assumption that all members of a cohort share some commonality is far from settled.

For example, why should we expect that young adults now in their teens and early twenties share much in common with those in their late-thirties? The oldest of these young adults entered the labor market during the Great Recession while the youngest have yet to even complete their schooling; the oldest witnessed first-hand the tragic events of 9/11 while the youngest were infants or not yet even born on that date. As sociologist Philip Cohen points out, youths born between 1980 through 1984 were in their late twenties when the 2009 recession hit, and many had already begun their childbearing careers. By contrast, youths born between 1990 and 1994 started their childbearing years at the height of the economic crisis, and at least so far have dramatically lower birth rates.

About Baby Boomers. Similarly, sociologists debate whether it is meaningful or useful to ascribe such commonalities to the Baby Boomers, commonly defined as people born between 1946 and 1964. The oldest of these spent their early years in the politically repressive and rigidly gendered 1950s while the youngest spent their childhoods surrounded by the Civil Rights movement and the early feminist movement of the 1960s, and both groups had significantly different same racial-ethnic, class, or regional experiences. The marriage rate has fallen fairly steadily since its high point in the 1950s and early 1960s. But the sharpest drop, a full 22 percent decline, occurred within the Baby Boom generation rather than being pioneered by Millennials.

The belief that birth cohorts have particular identities has become popular in marketing and consumer research because young people are especially receptive to adopting new styles of dress, music, and social practices in language and communication. There is no doubt that such tastes are shared among age peers; but there is some doubt about whether these stylistic commonalities persist in later life (probably not), and even more about whether they extend to widely shared world views about politics that are maintained for life (unlikely).

Think, for example, about whether Baby Boomers, who came of age in the 1960s and 1970s, have generally held onto to their views of the world as they entered mid- or later-life. On many issues, some have become more conservative, with a disproportionate share supporting Trump. But, a larger majority of Baby Boomers now support gender equality than did their 18-to-25 year old selves in the late 1970s and early 1980s.

Another way to look at generations and cohorts. Yes, new values and new behaviors often emerge among younger age groups as they encounter different social, political, technological, and economic conditions from those experienced by people who grew up ten, 20, or 50 years earlier. Some of the new conditions recent cohorts have experienced, different from those of their elders, may help explain why, on average, Americans born in recent decades have different attitudes than older cohorts on issues such as climate change. In a June 2015 survey, 60 percent of 18-29 year-olds said that human activity was causing global warming, almost twice as many as the 31 percent of Americans 65 and older. But, it is not clear whether this change is a distinctive view of the Millennial cohort. Only time will tell.

Another new development that has undoubtedly affected the beliefs and behaviors of younger Americans is that the timetable for growing up was dramatically altered in the second half of the 20th century. It now takes much longer for people to complete their education and attain full economic independence than it did 50 years ago (Furstenberg, 2010).

Young adults these days tend to flock to urban environments more than they once did, in part because of this postponement. Values about living arrangements, the pursuit of romantic and sexual relationships, and the timing of marriage have also been affected. But, these changes have been coming about gradually (since the 1980s) with each age group experiencing a later age of entry to adulthood and a larger share of residents in central urban areas. It is not obvious that these preferences are distinctly expressed by Millennials and that they will subside as a new cohort succeeds them.

It is often difficult to make the case that changing attitudes and behaviors are confined to a particular age group or that they will persist over time. Rather, a succession of age groups has responded to the new realities of the need for extended education to find a more secure footing in the labor market. In my recent research with Sheela Kennedy, we found that the timetable in expectations for coming of age changed not only among young adults but their parents and grandparents. Demographers would call this a “period effect” (influencing all age groups) rather than a “cohort effect” that is experienced by a single age cohort.

As the briefing papers by Pepin and Cotter and by Fate-Dixon show, attitudes about male-breadwinner families and working mothers have shifted away from an egalitarian direction among a significant section of the younger generation, even though acceptance of equal rights as a principle has continued to grow. It remains to be seen whether this trend represents a broader view in the general population that reflects new experiences in family life or whether it is a temporary expression of experiences or challenges occurring during a “stage of life” that is confined to an age grouping. Will it persist as young adults who are not yet in families move into partnership and parenthood? Will it abate if advocates for family-friendly work policies make gains? Or will it spread up the age ladder if economic and political developments make it even harder than it already is for men and women to share breadwinning and parenting? We simply don’t know, but answering these questions will tell us more about what is in store in the coming decades than fanciful generalizations about the identity of “the” Millennials, who are every bit as divided by race, ethnicity, religion, region, gender and sexuality as their elders.

Frank Furstenberg is Professor of Sociology and Research Associate in the Population Studies Center, University of Pennsylvania.