What makes some CEOs successful? The stereotypical view—often promoted in glowing media profiles of Fortune 500 icons—is that these leaders are charismatic, armed with Ivy League degrees, and larger than life. That impression of perfection is both superficial and wrong, according to Elena Lytkina Botelho WG99, a consultant at ghSMART, a Chicago-based management consulting firm. After a 10-year study that examined more than 2,000 CEOs and 17,000 executives, Botelho and her colleagues found that successful CEOs share four behavioral attributes that are often overlooked because they’re not particularly glamorous.

Decisive: It’s no surprise that successful CEOs need to be good decision-makers. But according to Botelho, it’s not necessarily the case that the best are also the most insightful. “It’s actually more frequent that CEOs stand out for the speed of their decision-making, not simply the quality,” she says. One example of the decisive leader is Amazon CEO Jeff Bezos. “He specifically talks about the fact that decision-making is quality times velocity,” Botelho says. Bezos calls Amazon a “Day One” company (dynamic; makes good decisions fast) rather than a “Day Two” business (successful, but not moving forward and shaping its industry).

Relentlessly Reliable: What sets many CEOs apart from the pack is that they actively seek out opportunities to be relied upon. In her research of highly successful CEOs, Botelho found that “they almost have a desperate hunger to be counted on and pull things together.” But being a relentlessly reliable leader doesn’t always mean taking control of the situation—it’s also about knowing when to defer to your managers. “You’ve got to surround yourself with people who have complementary skill sets, and you’ve got to let them do their job,” says Botelho. “You have to let them build reliability into the company and be willing to be part of that reliability.”

Master of Relationships: Being a CEO is a balancing act; you have multiple groups—shareholders, customers, and employees—who are all expecting you to satisfy their needs. One of the CEOs Botelho studied put it best when he said, “As a CEO, my job is to keep them all constructively dissatisfied.” Although dissatisfaction may not seem like the goal of a successful top executive, it speaks to the fact that maintaining relationships requires more than simply being likable. “He’s not thinking about how do I please my audience, but how do I bring everybody forward,” says Botelho, “even if at times they’re not going to be happy with what it feels like day to day.”

Adaptable: As the speed of technological advancement increases and global markets continue to fluctuate, the ability of a CEO to adapt to change is becoming more and more important. “I don’t know a single board, company, or set of investors that isn’t talking about how the world is speeding up, how there is a greater degree of uncertainty in the world, and how important innovation is in this environment of change and of constant surprises,” says Botelho. “You have to be able to position the business for success and remain vibrant and viable. Adaptability is on the rise as a key CEO behavior.”

Published as “What Today’s CEO Needs to Succeed” in the Fall/Winter 2017 issue of Wharton Magazine.