Lean in and lean out

Lean In: Women, Work, and the Will to Lead is a 2013 book written by Sheryl Sandberg, the COO of Facebook. According to the New York Times (Making a Word Meme):

“Lean in” is the idiom of the moment for headline writers, the Twitterati and New Yorker cartoonists. ...An avalanche of publicity accompanying the book’s release in March helped the expression gain a toehold in the cultural vernacular, but the phrase seems to have taken on a life of its own, even among (perhaps especially?) those who have not read the book.

The phrase had a life before Ms. Sandberg used it. It was frequently invoked in sports (lean in to the slope, lean in to the wave) and evolved into a metaphor for embracing risk, said Ben Zimmer, executive producer of the Visual Thesaurus and Vocabulary.com, and language columnist for The Boston Globe.

Ben Zimmer writes:

In winter sports like snowboarding and skiing, you might want to "lean into the turn." And "leaning in" is also seen as a good move in sports as diverse as rowing, boxing, football, baseball, horse-riding, riflery, motorcycling, and running.

From these different activities comes a general picture of "leaning in" (or "leaning forward") as a stance that suggests embracing risk and not shying away from difficulty or obstacles in one's path. It's not surprising, then, that "leaning in" should get applied to the business world.

He stated that the earliest use he could find to this metaphorical transfer comes in a 1941 issue of Princeton Alumni Weekly.

Dave Walton of Wordorigins.org states:

A possible progenitor for the Sandberg's use of the phrase is from interactive television, which has for at least 15 years been describing the difference between 'lean back' and 'lean forward' to denote the difference between TV and the Internet.

That might explain the Ngram takeoff in 1965 (with lean forward leading the pack).

Is lean out paired with lean in? Most likely, seeing the above.

• 'Lean in' is a physical activity, and did not have the metaphorical meaning that Sandberg gave it before her book (at least not to my knowledge).

• 'lean out' is also physical. It is a pair with 'lean in' grammatically, but Mayer is using it in a jocular fashion. The metaphorical meaning of 'lean in' is so new that a parallel metaphorical meaning for 'lean out' needs to ride on its coattails. That is to say that, even in the appropriate context of not wanting to stand up for oneself, if you used 'lean out' by itself with no mention of 'lean in', it would be hard to understand, people wouldn't get the idea.