Are generation theories proven? 7 reasons they’re dubious

Image Collage of Multi-Generational Staffers Taking Selfies

Illustration made available for sharing: CC BY-ND 3.0. Illustration and story by K. Patricia Bouweraerts.

The human brain tends to categorize experiences in an attempt to make order and sense of the world — however our conscious categorization of individuals by their birth years may well result in less understanding, rather than more.

Generation theories put individuals of certain birth years into sets such as Gen Z, millennial, Gen X, and baby boomer, each with supposedly similar values and behavioral qualities. It is an especially popular premise, with articles, consultant services, seminars, and webinars available with a click or two. Gen concepts can be found in college marketing textbooks despite the lack of professional agreement on the beginning and ending years of each age group.

Why aren’t more of us questioning it? There certainly is room for reasonable doubt concerning a system that places people into mass-generalized divisions.

David Costanza, associate professor of organizational sciences at George Washington University and a senior consortium fellow for the U.S. Army Research Institute, takes issue with gen distinctions, maintaining that the science to back them up is not there.

“In fact, solid evidence supporting generations, their characteristics, or even their existence, is lacking,” wrote Costanza in Slate. “In short, the science shows that generations are not a thing.”

When considering the broader scheme of things, it is no longer acceptable to categorize individuals by ethnicity, ability, and gender. Yet, generalizing people by age group appears to be the 21st century frontier for bias.

There are at least seven major demonstrable reasons — most likely more — for us to stop perpetuating generation theory structures.

Reason one: studies point to life stage and period effect, not generation

When young adults come of age, there are comparable life tasks such as starting to work and finding a significant other, whether their birthday was in 1965 or 1985. When adults reach 65, they face similar financial changes no matter if they were born in 1935 or 1955.

“For example, millennials score lower on job satisfaction than Gen Xers, but are millennials really a less satisfied generation,” Costanza asked. “Early in their careers, Xers were also less satisfied than baby boomers. As people get older, they are more likely to leave jobs they do not like and migrate toward ones they do. …This is an age effect, not a generational effect.”

It is generally accepted that young people throughout time have been idealistic, invincible-feeling, and somewhat narcissistic.

“Our research shows that while narcissism among young people did increase slightly through the mid-2000s (about 1.8 points on a 40-point scale), it is now back to where it was in the 1980s,” he added. “That’s right, on average, millennials are no more narcissistic now than Xers or boomers were when they were in their 20s, and one study has even found they might be less so than generations past.”

Jessica Kriegel, Ed.D. presents another argument supporting the age effect rather than a generational one in her article, “Why Generational Theory Makes No Sense.” She writes as a brand contributor for Oracle on, and is a researcher, speaker, and author on the topic of generational dynamics.

“If a generation were truly to be defined by the historical and cultural circumstances in which they were reared, then logic would have it that their defining traits would remain the same irrespective of age,” Kriegel wrote. “Once frugal, always frugal; once family-oriented, always family-oriented.”

Kriegel points out that those who came of age during the Great Depression experienced the impact of substantial poverty, leading to their gen being labeled the frugal cohort.

“In the aftermath of World War II, the economic boom of the 1950s gave birth to the concept of ‘keeping up with the Joneses’ — a car in every garage and a television in every living room,” she added. “So the children who lived through the Great Depression, now described as frugal in their old age (living on a fixed retirement income), were the (unthrifty) Joneses in the 1950s.”

Young Woman Reading A Newspaper

Newspapers and books are a tactile experience for individuals of any age. Photo by Roman Samborskyi via

In addition, Costanza offers an example of the “period effect” rather than a generational one.

“Research shows that millennials joining the Army now show more pride in their service than boomers or Xers did when they joined 20-plus years ago,” he wrote. “Is this a generational effect? Nope. Everyone in the military now shows more pride on average than 20 years ago because of 9/11. The terrorist attack increased military pride across the board.”

Reason two: the birth years of the groups are inconsistent

Generational Theory was popularized with the 1991 book “Generations: The History of America’s Future, 1584–2069,” by sociologists William Strauss and Neil Howe. They wrote that there are uniquely-defined 18–20-year birth-year cohorts, and each group’s members share many values and characteristics, according to Kurt Cagle, contributing editor for the Cognitive World section of

Rebecca Onion, Ph.D., who has written for the Boston Globe, Slate, and Aeon magazine, agrees.

She writes in her piece “Against generations,” that Strauss and Howe also suggested a turning point, or crisis, happens about every 80 years. They founded the company LifeCourse Associates, LLC based on their cyclical generations theories.

“While the pair’s ideas seem far-fetched, they have currency in the marketplace: LifeCourse Associates has consulted for brands such as Nike, Cartoon Network, Viacom and the Ford Motor Company; for universities including Arizona State, Dartmouth, Georgetown and the University of Texas, and for the US Army, too,” she added.

The boom generation is listed as 1943–1960, Generation X from 1961–1981, and the millennial generation from 1982–2004, according to at the date of this writing. However, Cagle thinks the boundary dates of gens are better determined using the data of total yearly births in the U.S. and the resulting economic growth or contraction.

“So, to summarize, an Inflection Point Generation occurs when there is a clear behavioral trend change, typically a peak or trough point, in the birth rate,” he wrote.

Cagle marks the baby boomer years from 1936–1956, Gen X from 1957–1975, and millennial Gen Y from 1976–1990. He was born in 1963 and calls himself “an IP GenXer,” having values that line up with Gen X.

Further, Pew Research Center defines these three sample gens differently from either of the above systems.

Michael Dimock, president of Pew Research Center wrote in “Defining generations: Where Millennials end and Generation Z begins,” that baby boomers were born between 1946–1964, Generation X from 1965–1980, and millennials from 1981–1996.

It appears there is lack of agreement between generational year dates. Dimock added that the end year of 1996 for the millennial gen is also debated by those who define gen date ranges.

“Perhaps, as more data are collected over the years, a clear, singular delineation will emerge,” he explained. “We remain open to recalibrating if that occurs. But more than likely the historical, technological, behavioral and attitudinal data will show more of a continuum across generations than a threshold. As has been the case in the past, this means that the differences within generations can be just as great as the differences across generations, and the youngest and oldest within a commonly defined cohort may feel more in common with bordering generations than the one to which they are assigned.”

Typically in scientific research, when a study is replicated with the same results, it solidifies those initial findings. With the generations hypothesis, though, the results seem to keep changing.

In addition, an individual born at the beginning of a range may develop different values and characteristics than someone who is a child at the end of the range.

The civil rights movement stands to have made quite a significant impact on a teen who was born in 1950s Los Angeles, while perhaps little impact on a child born in the rural or suburban Midwest in 1962 whose parents sheltered them from television reports, or was simply distracted with BarbieTM dolls and LEGO® toys at age six in 1968.

Reason three: gens are too large for specific categorizations

What if the characteristic called “resistant to change” is not a factor of the gen you are born into, but more based on interests or personality?

Photo of Tim Berners-Lee Speaking at an Event

Tim Berners-Lee, born in 1955, inventor of the World Wide Web, speaking at the launch of the World Wide Web Foundation. Photo by Scott Henrichsen, via Wikimedia Commons, Creative Commons Attribution 2.0 Generic license.

After all, those born between the years 1946–1964 developed technology that has largely transformed society and culture. These life-changing inventions include the World Wide Web, Apple II, DNA fingerprinting, optical character recognition, the automated external defibrillator (AED), and disposable cell phones, according to Reuters.

Kriegel has studied how individuals of different ages respond to training delivered via technology.

“As part of my doctoral work, I did a peer-reviewed study of differences in learning style preferences across four generations of employees at a railroad company,” Kriegel explained. “I asked the participants to select their top five favorite technology-based learning activities from a list of 22 and found that the preferences of all four generations were strikingly similar.”

The large size of some of the generations magnifies the difficulty in predicting specific qualities. Constanza compared the accuracy of predicting characteristics of large gens to a model of national culture. According to one model, U.S. citizens typically are more individualistic, indulgent, and disliking of hierarchy — while people who live in China are to a greater extent group-oriented, restrained, and accepting of hierarchy.

“However, these countries are so large and diverse that they each have millions of individuals who are more similar to the ‘averages’ of the other country than to their own,” Costanza wrote. “There is more variation within countries than between them, and thus figuring out exactly what characteristics truly represent a nation’s culture is almost impossible. Generations data has the same problem.”

Reason four: different terms are used for nearly the same concepts

In gen theories, those who are members of the boom are thought to be selfish — the “me” generation, and millennials are called narcissistic and entitled. But there does not appear to be much of a difference between selfish and narcissistic; the terms are fairly alike.

Millennials are reported to rely on product recommendations from peers, friends, and social networks rather than on advice from experts, according to the U.S. Chamber of Commerce Foundation. They read user reviews of brands and services on mobile devices.

Given the internet, researching a product oneself is a practical alternative to relying on an expert recommendation. There are also members of other age groups, though, who initially look up restaurant, hotel, clothing, and electronic device reviews online.

On the other hand, why are TED Talks admired and trendy? These speakers have deep knowledge on a topic, and Talks are attended by an audience much like a lecture presented by an expert.

Could it be because now we don’t call it an expert lecture … we call it “thought leadership?”

Reason five: statistical techniques fail to prove generational divisions

Group of Businesswomen Taking Selfie at Office Cafeteria

A workplace can be age-blind. Photo by ammentorp, via

Costanza lists some of the models involved in gen research, including the following:

  • Analysis of variance (ANOVA)
  • Cross-temporal meta-analysis (CTMA)
  • Cross-classified hierarchical linear modeling (CCHLM)

Researchers have found varying results based on which of the statistical techniques was used and when the data was gathered. One of the models above showed that the least stressed workers were members of the silent generation, and another that all generations were equally stressed, he wrote.

“Or looking at job satisfaction again through a different lens, ANOVAs generally showed that millennials were lowest, CTMAs sometimes showed millennials were lowest and sometimes Xers were lowest, and CCHLM found either a small generational effect or nothing at all,” Costanza added. “It is hard to argue that generations are a thing if evidence for them depends so heavily on which statistic is used.”

Reason six: gen theory perpetuates discrimination

Onion argues that gen theories are based on evidence from cherry-picked samples and ideas gathered from white and middle class populations.

”In an article in The Chronicle of Higher Education in 2009 on the pundits and consultants who market information about ‘millennials’ to universities, Eric Hoover described Howe and Strauss’s influential book about that generation, ‘Millennials Rising: The Next Great Generation (2000)’, as a work ‘based on a hodgepodge of anecdotes, statistics, and pop-culture references’ with the only new empirical evidence being a body of around 600 interviews of high-school seniors, all living in wealthy Fairfax County, Virginia.”

Individuals who are other than white middle or upper socioeconomic class may have had fundamentally different experiences during societal and technological upheavals.

“Fred A Bonner II, now at Prairie View A & M University in Texas, pointed out that many of the supposed ‘personality traits’ of coddled and pressured millennials were unrecognizable to his black or Hispanic students, or those who grew up with less money,” Onion wrote. “Siva Vaidhyanathan, a cultural historian and media scholar at the University of Virginia, told Hoover: ‘Generational thinking is just a benign form of bigotry.’”

Gen theories put labels on individuals, much like we used to label women as the “gentler” sex, better at keeping the home neat and arranging scarves and furniture.

“We are (mostly) past it being acceptable to stereotype and discriminate against women, minorities, and the disabled,” Costanza wrote. “Why is it OK to do so to millennials or boomers?”

Even the designation “boomer” is emotionally charged and may be perceived as derogatory.

Onion has observed that the generations in her own family exhibit characteristics of her group, Gen X.

“Since I’m a ‘Gen-X’er born in 1977, the conventional wisdom is that I’m supposed to be adaptable, independent, productive, and to have a good work/life balance,” Onion wrote. “Reading these characteristics feels like browsing a horoscope. I see myself in some of these traits, and can even feel a vague thrill of belonging when I read them. But my ‘boomer’ mother is intensely productive; my ‘Greatest Generation’ grandmother still sells old books online at age 90, in what I consider to be the ultimate show of adaptability and independence.”

Reason seven: some are getting rich from promoting gen theories

Two Smiling Male Office Colleagues Taking a Selfie, One Older and One Younger

Gen theories may be debatable. Photo by Volodymyr Melnyk, via

As writers and journalists use age-grouping terminology in everyday language and reports, the terms become part of the wallpaper of American conversation.

“In the end, the core scientific problem is that the pop press, consultants, and even some academics who are committed to generations don’t focus on the whys,” Costanza added. “They have a vested interest in selling the whats (‘Generation Me’ has reportedly sold more than 115,000 copies, and Google ‘generations consultants’ and see how many firms are dedicated to promulgating these distinctions), but without the science behind them, any prescriptions are worthless or even harmful.”

Remember the mislabeling of those who lived through the Great Depression as forever frugal?

“Examples such as these are endless, yet the media and Gen-Experts still perpetuate the myth of generational differences,” Kriegel wrote. “We must begin to see generational theory for what it is: an opportunistic fad that exaggerates differences between generations to no real benefit except to the Gen-Experts themselves.”

It is now a widespread practice to place people into generational categories so we can better market to them — and it all seems to be fine and good until someone tells you or me that we do not have a grip on technology by circumstance of our birth year, or have a grip on our ego by virtue of the gen we’ve lucked into.


Initially published on by the writer on March 30, 2020.

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