Anyone who says that performance reviews are useful is full of it. Really, who comes out of a review feeling the least bit enlightened or empowered? Certainly not the employee.

“My view and experience is that they are worthless up until they're not,” says a senior associate at a big firm. Most reviews are anodyne, she adds, particularly for junior and midlevel associates, “Unless you're getting fired.”

To be perfectly cynical, I think the performance review is a handy management tool to justify paying crummy raises or firing an employee—whatever the need might be. That's why perfect scores on reviews are virtually nonexistent, and there are always areas for employee “improvement” on evaluation forms. It's also why some companies grade employees on a curve. That way, the standards are vague, and no employee should feel in the least special. Talk about boosting morale!

We all know reviews are empty annual rites, but who would have the balls to get rid of them?

Brace yourself. It's Allen & Overy, an old-line law British firm.

Legal Business reports that the firm dropped its annual appraisals more than six months ago.

Instead of the formal annual review, there's now a “consistent feedback and dialogue,” says Elizabeth Mercer, A&O's corporate public relations manager. She tells me it is a “pilot scheme” started last October, involving “500 fee-earners and business staff across several practice groups and support functions in London, Singapore and the Middle East.”

And how are tradition-bound lawyers reacting to this decimation of their routine? They love it.

“The feedback on this has been positive,” Mercer says, “particularly in engaging with female associates on their career development. We didn't do it originally to retain female talent, but the positive feedback has been noticeable.” Dropping the annual evaluation has been so well received that more offices and practice groups worldwide will do the same by year end, Mercer says.

So here's the newsflash: Everyone hates performance reviews—but women really loathe them.

Surprised? Well, you shouldn't be.

Studies have shown that performance reviews are riddled with gender bias, and that women are often judged much more harshly than men. For instance, one study finds that men outscored women in numerical ratings, though women often got glowing comments on the narrative portion of the reviews. (The study analyzed the performance reviews of 234 associates at a Wall Street law firm.)

“The [American Bar Association] Commission on Women in the Profession recognized the problem of implicit biases in evaluations many years ago,” says Roberta Liebenberg, the commission's former chair. “Double standards are often applied.” Men get praised for aggressive behavior, she says, “while the same behavior by female associates is criticized.” Moreover, she adds, “Mistakes by male associates are more readily forgiven than those made by their female counterparts; and male associates are judged more often on potential, while women associates are judged based solely on their performance.”

In light of these studies and the positive reaction A&O has gotten by dropping its annual evaluations, doesn't it make sense that other law firms and companies abandon this annual ritual of meaninglessness?

Of course. But what are the chances that will happen?

“I think this is a very surprising and welcome development, but am somewhat skeptical that other firms will follow their lead,” Liebenberg says.

Let me be even more blunt: Allen & Overy is an outlier. But in my book, that's a compliment.