Book Preface

The How and Why of Generations

In the Bay of Bengal between India and Myanmar lies North Sentinel, an island about the size of Manhattan. In 2018, a 26-year-old American paid a group of fishermen to take him there. He was never seen again.

North Sentinel is the home of one of the last groups of humans isolated from the rest of the world. Outsiders have visited over the centuries, including a group of anthropologists between the 1960s and 1990s, but the tribe has made it clear they want to be left alone. Boats and helicopters that get too close are greeted by tribesmen waving spears and bows, and the few lone outsiders who have ventured there have been killed, leading India to ban boats from traveling within a three-mile radius of the island. Although the tribe uses metal from shipwrecks for their weapons, they have no modern technology. Their day-to-day lives today are, in all likelihood, barely different from how they were two hundred years ago.

As a result, parents on North Sentinel are not shooing their kids off video games and telling them to go outside and play. Parents are not worrying that their teenage children are spending too much time on TikTok. They are hunting, gathering, and cooking over an open fire instead of picking the best Amazon Fresh delivery window. With no birth control, young women on the island have children at about the same age that their mothers, grandmothers, and great-grandmothers did. We can guess that cultural values have changed little; the North Sentinelese likely follow the same rules for communal living as their ancestors.

Not so in most of the rest of the world. New technologies have reshaped social interaction and leisure time, value systems have shifted from rigid rules and strict social roles to individual expression and an embrace of diversity, and the milestones of adolescence and adulthood are now reached much later than they were seventy years ago. A time traveler from 1950 would be shocked that same-sex marriage was legal—and then they’d probably faint after seeing a smartphone.

The breakneck speed of cultural change means that growing up today is a completely different experience from growing up in the 1950s or the 1980s—or even the 2000s. These changes have an impact: The era when you were born has a substantial influence on your behaviors, attitudes, values, and personality traits. In fact, when you were born has a larger effect on your personality and attitudes than the family who raised you does.

These differences based on birth year are most easily understood as differences among generations. Traditionally, the word generation has been used to describe family relationships—for example, that a three-generation household includes grandparents, parents, and children. The word generation is now more commonly used to refer to social generations: those born around the same time who experienced roughly the same culture growing up.

The United States is currently populated by six generations: Silents (born 1925–1945), Boomers (1946–1964), Generation X (1965–1979), Millennials (1980–1994), Generation Z (aka iGen or Zoomers, 1995–2012), and an as-yet-unnamed generation born after 2013 (I call them Polars; some marketers have called them Alphas). Generations aren’t just an American phenomenon; most other countries have similar generational divisions, though with their own cultural twists.

Not that long ago, it was difficult to determine whether and how generations differed from each other, even on average. More than one pundit has complained that musings on generations occasionally resemble horoscopes. They have a point: Many books and articles on generational differences are long on subjective observations but short on hard data. Others poll a small segment of people and attempt to draw broad conclusions. With the age of Big Data upon us, that no longer needs to be the case. In these pages, you’ll find the results of generational analyses spanning twenty-four datasets including thirty-nine million people—nearly as many people as live in California, the most populous state in the U.S. With so much data, it’s possible to get a better understanding of generational differences than ever before.

Appreciating generational differences is crucial for understanding family relationships (Why is my teen always on her phone? Why do my parents not know what nonbinary is?), the workplace (Why are younger employees so different? Why does my boss think that way?), mental health (Which generations are more likely to be depressed, and why?), politics (How will each generation vote as they grow older?), economic policy (Are Millennials actually poor?), marketing (What does each generation value?), and public discourse (Why are more young people so negative about the country? Is putting your pronouns in your email signature just a fad?). These questions capture just a few of the reasons why generations are endlessly discussed online. At a time when generational conflict—from work attitudes to cancel culture to “OK, Boomer”—is at a level not seen since the 1960s, separating the myths from the reality of generations is more important than ever.

Studying the ebb and flow of generations is also a unique way to understand history. Events such as wars, economic downturns, and pandemics are often experienced differently depending on your age. Having Dad at home because he was laid off during the recession might be fun for the kids but terrifying for Dad. However, history is not just a series of events; it’s also the ebb and flow of a culture and all that entails: technology, attitudes, beliefs, behavioral norms, diversity, prejudice, time use, education, family size, divorce. What your grandmother called “living in sin” is today’s accepted unmarried partnership. What a teenager now considers entertaining (Instagram scrolling) is very different from what her parents considered entertaining when they were teens (driving around with their friends).

Generational differences also provide a glimpse into the future. Where will we be in ten years? Twenty? Because some traits and attitudes change little with age or change in predictable ways, the data—especially on younger people—can show us where we are going as well as where we are. Although people continue to change throughout their lives, our fundamental views of the world are often shaped during adolescence and young adulthood, making the younger generations a crystal ball for what is to come.

I’ve spent my entire academic career—more than thirty years—studying generational differences. It all began when I noticed something odd while working on my college honors thesis in 1992: College women in the 1990s scored as significantly more assertive and independent on a common personality test than their counterparts in the 1970s. But this was at the University of Chicago, where everyone is a little weird, so I thought it might just be a fluke. After getting the same result the next year with undergraduates at the University of Michigan (who were considerably less weird), I realized there might be something more systemic going on. A few months of library work later, I’d found a steady rise in college women’s self-reported assertiveness and independence across 98 psychology studies from 1973 to 1994—a result that made perfect sense given the shift in women’s career aspirations over that time. I’d documented my first generational difference.

Over the coming years, I would gather studies from scientific journals ensconced on dusty shelves, finding generational differences in personality traits, self-views, and attitudes. By the mid-2000s, large, nationally representative datasets became accessible online, including the results of huge surveys of young people conducted across the country since the 1960s. Other sources of data, like the Social Security Administration database of baby names and Google’s huge database on language use in books, both of which draw from data going back to the 1800s, appeared online as well, giving additional glimpses into how the culture was changing.

Seeing big shifts in self-confidence, expectations, and attitudes around equality, I wrote a book on Millennials, called Generation Me, in 2006. When optimism plummeted and teen depression rose during the smartphone era, I wrote a book on Generation Z, called iGen, in 2017. But as I traveled the country giving talks about iGen, managers, parents, and college faculty would ask, “But hasn’t new technology affected all of us?” Or they’d want to know, “Do other generations also look different now from before?” This book is the answer to those questions—and to many others about Silents, Boomers, Gen X, Millennials, Gen Z, and Polars.

To begin, let’s consider two broader questions. First, what causes generational differences? And second, how can we discover the actual differences among generations?