For years many of the HR chiefs she recruited reported to the COO or the CFO and complained that they lacked real influence in the C-suite. Today, she says, they often report directly to the CEO, serve as the CEO’s key adviser, and make frequent presentations to the board. And when companies search for new CHROs, many now focus on higher-level leadership abilities and strategy implementation skills. “This role is gaining importance like never before,” Filler says. “It’s moved away from a support or administrative function to become much more of a game changer and the person who enables the business strategy.”

To investigate the CHRO role within the C-suite, Filler worked with Dave Ulrich, a University of Michigan professor and a leading consultant on organization and talent issues. In looking at several sets of data, they found surprising evidence of the increasing responsibility and potential of CHROs.

First, in order to understand the importance of the CHRO relative to other C-suite positions, including CEO, COO, CFO, CMO, and CIO, Filler and Ulrich looked at salaries. To identify the best performers, they found the top decile of earners in each role. Then they averaged the annual base compensation of each group. No surprise: CEOs and COOs are the highest-paid executives. But CHROs are next, with an average base pay of $574,000—33% more than CMOs, the lowest earners on the list. “Great CHROs are very highly paid because they’re very hard to find,” Ulrich says.

The researchers also studied proprietary assessments administered by Korn Ferry to C-suite candidates over more than a decade. They examined scores on 14 aspects of leadership, grouped into three categories:

• Leadership style, or how executives behave and want to be perceived in group settings
• Thinking style, or how they approach situations in private
• Emotional competency, or how they deal with such things as ambiguity, pressure, and risk taking.

The researchers then assessed the prevalence of these traits among the different types of executives and compared the results.Their conclusion: Except for the COO (whose role and responsibilities often overlap with the CEO’s), the executive whose traits were most similar to those of the CEO was the CHRO. “This finding is very counterintuitive—nobody would have predicted it,” Ulrich says.

The discovery led Filler and Ulrich to a provocative prescription: More companies should consider CHROs when looking to fill the CEO position. In the modern economy, they say, attracting the right talent, creating the right organizational structure, and building the right culture are essential for driving strategy—and experience as a CHRO makes a leader more likely to succeed at those tasks. The advice comes with some caveats. First, Filler and Ulrich studied only the best performers, so they’re pointing to a small subset of CHROs as having corner-office potential. They don’t see a path to the top job among people who have spent their careers in HR; instead, they are touting the prospects of executives who have had broad managerial experience (and P&L responsibility) that includes a developmental stint running the HR department. They emphasize that any CHRO who aspires to become a CEO must demonstrate capabilities in a host of skills required of top leaders. “The challenge for CHROs is to…acquire sufficient technical and financial skills, in early education and in career steps along the way, if succession to CEO is a desired outcome,” they write in a white paper about their research. Indeed, some companies, including Zurich Insurance, Nestlé, Philip Morris, and Deutsche Bank, do put high-potential executives through a developmental rotation in a high-level HR job.

Filler and Ulrich highlight two examples of prominent CEOs who had developmental stints in HR earlier in their careers. Mary Barra, the CEO of General Motors, served as the carmaker’s vice president of HR for 18 months, and Anne Mulcahy, Xerox’s CEO from 2001 to 2009, ran that company’s HR operations for several years in the early 1990s. It’s no coincidence that both are women: According to the researchers’ data, 42% of high-performing CHROs are female—more than double the share in the CMO position, the next highest (16%). One implication: If more companies envisioned CHROs as potential CEOs, the number of female CEOs could dramatically increase.

In their white paper Ulrich and Filler also report on what CEOs and CHROs have to say about the changing nature of the top HR role. Several CEOs see the CHRO as C-suite consigliere. “It is almost impossible to achieve sustainable success without an outstanding CHRO,” says Thomas Ebeling, the CEO of the German media company ProSiebenSat.1 Media AG and a former CEO of Novartis. “[The CHRO] should be a key sparring partner for a CEO on topics like talent development, team composition, [and] managing culture.”

Peter Goerke, the London-based group director for HR at Prudential, agrees with Filler and Ulrich that although deep skills in marketing or finance might once have given CEO aspirants a significant competitive advantage, today a broader set of people-focused skills can be more useful. “Succession to a CEO role requires a balance of technical and people skills,” he says. “For all C-suite roles, and often at least one level down, there has been a gradual shift in requirements toward business acumen and ‘softer’ leadership skills. Technical skills are merely a starting point.”

In spite of the historic bias against the CHRO function, the rising status of HR leaders is not entirely surprising. Over the past 20 years Jim Collins and other management theorists have focused on talent strategy as the prime determinant of corporate success—an idea Collins popularized in phrases such as “Get the right people on the bus” and “First who, then what.” In her work recruiting CHROs, Filler has seen a growing recognition that those aphorisms hold true. “If you don’t have the right people in the right places—the right talent strategy, the right team dynamics, the right culture—and if you don’t proactively manage how an organization works from a culture and a people perspective, you’re on a serious path to disaster,” she says. Conversely, a top-notch CHRO can help a company plot a more successful future.