The Defining Decade (2012)

Our “thirty-is-the-new-twenty” culture tells us that the twentysomething years don’t matter. Some say they are an extended adolescence. Others call them an emerging adulthood. But what if thirty is not the new twenty? Meg Jay argues that twentysomethings have been caught in a swirl of hype and misinformation, much of which has trivialized what is actually the most transformative period of our adult lives.

Drawing on more than ten years of work with hundreds of twentysomething clients and students, Jay weaves the latest science of the twentysomething years with behind-closed-doors stories from twentysomethings themselves. The result is a provocative read that provides the tools necessary to make the most of your twenties, and shows how work, relationships, personality, social networks, identity, and even the brain can change more during this decade than any other time in adulthood–if we use this time well.

The Defining Decade has sold more than 500,000 copies in all formats and has been translated into more than a dozen languages. The related TED talk — “Why 30 Is Not the New 20” — has been viewed more than 10 million times.


“The professional and personal angst of directionless twentysomethings is given a voice and some sober counsel in this engaging guide. While Jay maintains that facing difficulties in one’s 20s ‘is a jarring–but efficient and often necessary–way to grow,’ the author is sincere and sympathetic, making this well-researched mix of generational sociology, psychotherapy, career counseling, and relationship advice a practical treatise for a much-maligned demographic.”
– Publishers Weekly

“A clinical psychologist issues a four-alarm call for the 50 million twentysomethings in America…..”
– Kirkus Reviews

“Any recent college grad mired in a quarter-life crisis or merely dazed by the freedom of post-collegiate existence should consider it required reading.”
– Slate

“Meg Jay takes the specific complaints of twentysomething life and puts them to diagnostic use.”
– The New Yorker