“Gen Z is soft, millennials are embarrassing, boomers are evil, and no one has thought about Gen X in years. Even if we can’t remember exactly which ages define each cohort, many people can offer up these generational stereotypes on command. These supposedly profound differences have been used to explain shifting attitudes about certain colors, the rising popularity of spicy foods, and even the perceived onset of adulthood. But while generational framings are ubiquitous, just how real are these fault lines?

The Pew Research Center has spent decades conducting surveys and research about what each generation thinks, feels, and is doing. Its start and end dates for generations became the standard for news publications, academic research, and dinner-table arguments. But late this spring, Pew announced it would no longer use generational labels such as millennial and Gen Z in its research. In doing so, Pew quietly ended a tradition that had in recent years become a source of growing frustration (and heated debate) in social-science circles.

The problem, said Kim Parker, the center’s director of social-trends research, is that what we call a generation covers too wide of a time span to offer any useful insight. Generations span 15 to 18 years, Parker explained to me in an email, making it challenging to home in on a handful of attributes that realistically apply to the whole group. A 27-year-old is likely to experience today’s lightning-fast social and technological changes differently than a 39-year-old, for instance, though both are considered millennials under Pew’s definition. And it may be hard to generalize about a generation whose eldest members were already in the workforce when the 2008 recession hit but whose youngest were just leaving elementary school.”