Michelle Obama has raised two apparently successful daughters, maintained an enviable marriage in the face of unbelievably trying circumstances, built her own thriving career before becoming first lady, and recently added the title of best-selling author to her list of accomplishments with the release of her new book, Becoming.

If anyone should have figured out how to have it all, it's clearly this rock star.

But according to the woman herself, even Michelle Obama can't figure out how to simultaneously balance a big job and a hands-on family life. The former first lady didn't mince words at a recent event for her book tour at the Barclays Center in Brooklyn.

"That s**t doesn't work all the time."

"That whole 'so you can have it all.' Nope, not at the same time," Obama told the crowd, according to The Cut. "That's a lie."

But what if you lean in, you might reply. After all, Facebook COO Sheryl Sandberg famously promised in her book of the same name that women can manage to rise in their careers without sacrificing the other areas of their lives if they just change how they approach work, negotiations, and advocating on their own behalf.

Obama, however, isn't buying it (to put it mildly). She was even more blunt in her assessment of Sandberg's advice. "And it's not always enough to lean in, because that s**t doesn't work all the time," she added.

Obama quickly apologized for the profanity -- "I forgot where I was for a moment!," she said -- but she did nothing to walk back her dismissal of Sandberg's advice. And, it turns out, Obama has science, as well as experience, on her side.

Psychology says "leaning in" can backfire badly.

What could possibly be wrong with Sandberg's go-get-em-girl pep talks and sensible-sounding advice? One strand of criticism notes it's way harder to lean in if you don't have the sort of privileges and support that Sandberg enjoys. Sandberg, to her credit, has acknowledged this reality since the tragic loss of her husband forced her into the role of single parent.

But, according to an even more vocal group of skeptics, the real trouble is that Sandberg's approach implies it's up to women alone to fix the problem of gender inequality. Companies don't have to become more accommodating and less biased if all that's needed for more women to rise is for them to change their behavior. Sandberg puts all the onus on women and none on institutions and society.

It's an objection that makes logical sense, but a trio of Duke psychologists wanted to test this complaint with rigorous science. To do so, they recruited 2,000 Americans, showing half of them texts and videos explaining Sandberg's DIY approach to fighting discrimination. The other half saw materials that stressed social factors holding women back. The researchers then surveyed everyone about their beliefs around gender disparities.

The good news is that Lean In is empowering. After reading Sandberg's advice, participants believed women had the ability to overcome obstacles. But there was a big catch -- they also blamed women who didn't succeed, even if their troubles were objectively caused by bias. This belief, in turn, made them more skeptical of broader initiatives that might tackle that bias (like these).

"We are by no means suggesting Sandberg intended to blame women for inequality," the psychologists behind the study conclude in their HBR write-up of the findings. "But we do fear that Lean In's main message -- which emphasizes individual action as a way to address gender inequality -- may lead people to view women as having played a greater role in sustaining and even causing gender inequality."

Obama didn't go into why she's personally so skeptical of Sandberg's prescriptions, but if she had wanted to this study would have provided plenty of ammunition. Sandberg's advice can clearly be useful in particular situations, but as Obama put it, "that s**t doesn't work all the time." 

Sometimes, it's society or the company that needs to change, not an individual employee.