This article originally appeared in WSJ.com's The Experts.

Even after a quarter century of efforts to bring parity to the workplace, most talented businesswomen still live down to expectations. Their aspirations for top leadership roles, and their confidence in attaining such roles, drop early in their careers and never recover.

The antidote: Meaningful career support from women’s direct managers.

Bain & Company recently completed a study that asked more than 1,000 men and women in a mix of U.S. companies two questions: “Do you aspire to top management?” and, “Do you have the confidence you can reach top management?”

At first, they do. Women with two years or fewer of experience actually lead men in ambition by a small margin. But for women with more than two years on the job, aspiration and confidence plummet 60% and nearly 50%, respectively. These declines come regardless of marriage and motherhood status and are far more significant than for men, who experience only a 10% dip in confidence.

When we asked more-senior managers the same questions, the percentage rises for both genders, but women never regain the level of aspiration that newcomers had. It remains 60% lower than men, whose rates shoot up. The percentage of male more-senior managers who have confidence that they will reach top jobs is almost twice the percentage of female managers.

One seemingly benign source of these dashed expectations is corporate newsletters and off-site meetings that celebrate men for pulling all-nighters or networking their way through the golf course to land the big account. When corporate recognition and rewards focus only on those behaviors, women feel less motivated and perhaps less able to try to make it to the top.

One woman told us that she was demoralized during her firm’s recent management retreat “watching middle-aged white male after middle-age white male tell their war stories of sacrificing everything to close the sale. I just kept sinking lower in my chair and thinking that I would never want to make it to the senior ranks if this was what it took.”

This culture is reflected in the answers to a second set of questions: “Do you see yourself fitting into the typical stereotypes of success within the company?” and “Have your supervisors been supportive of your career aspirations?” New workers of both genders have similar responses to the questions. But more experienced workers answer very differently. Women’s confidence that they matched the corporate ideal dropped by 15 percentage points, men’s by just nine points. Women’s sense that their supervisors supported than career goals was 20 points lower; men’s was just three points lower.

Many women shift their priorities toward non-work interests later in their careers. They value having a personal life over meeting the organization’s demands at all hours. Nuanced skills such as the ability to juggle several projects effectively or move a team to higher productivity may lead to better performance than merely spending more time at work. However, survey responses show that the “always on” stereotype remains an important model for ambitious employees to reckon with.

As for meaningful career support from direct managers, few women receive it. Some women told us their direct supervisors don’t know their career aspirations, or what to say or do to support them. Others reported feedback like “you’re not cut out for” top management, or “you don’t really want it.”

What’s not happening are discussions of goals, career strategies, job satisfaction, overall trajectory and—especially—the simple giving of real encouragement. While every insecure overachiever needs encouragement, our research clearly demonstrates that, because of gender differences, men get it more frequently than women. If the conversations don’t take place, the needed affirmation can’t happen.

That is a huge missed opportunity, because positive affirmation creates huge benefits. Having engaged employees assures better business outcomes and more loyal customers.

Corporate mandates and formal programs matter, but they’re not enough. The real work of gender parity involves carefully managing and nurturing the middle of the talent pipeline, then tracking the results. Companies should focus their efforts there, so that women can live up to their expectations.

James Allen is co-leader of the global strategy practice at Bain & Company.