emma stone Emma Stone, age 26. Dimitrios Kambouris / Getty

The 20s are called the "defining decade" for a reason.

Your personality takes shape, plus you make choices about your career, marriage, and where you're going to live.

It's also the time when you set your earning trajectory, according to a report released by the Federal Reserve Bank of New York.

"Across the board, the bulk of earnings growth happens during the first decade," write authors Fatih Guvenen, Fatih Karahan, Serdar Ozkan, and Jae Song.

The report — which we originally spotted on the Washington Post's Wonkblog — is the result of the economists' studying the career paths of 5 million workers over nearly 40 years.

"Workers projected to earn the median lifetime amount will see pay swell 38% from age 25 to 55, with the strongest upswing in the first decade," the Post reports.

The plateau is profound: For the median group of lifetime earners, the average earnings increase from age 35 to 55 is zero.

This makes the 20s look even more crucial than before.

It's where you choose your trajectory, then maximize it as best you can.