"Credible leadership is evident in the success of any business," says one entrepreneur.

From what sources does leadership arise? It can come from many places, but in the majority of cases, leaders credit some event or relationship in their early lives with shaping the people they eventually became.

Former Medtronic CEO Bill George, now a Harvard Business School professor, interviewed 125 people deemed to be successful and authentic leaders for his book, True North: Discover Your Authentic Leadership.

To his surprise, one thing almost all had in common was that they traced their leadership traits to some crucible life event, transforming experience or just a "growing up" experience they'd had earlier in life.

Starting the project, George's team expected those they interviewed would talk about the traits, characteristics and leadership styles that made them successful. Instead, they spoke about how their passions arose from their life stories, and there was a consistency in that thread across almost all of the 125 leaders interviewed that at first surprised the researchers.

That same thread quickly becomes apparent in conversations with today's business leaders, such as Thompson. "Throughout life, I have had mentors, friends and partners who have influenced my thinking as well as transformed me into the person I am now," he says. To this day, he still checks in with some former bosses who functioned as mentors to gauge how well he is applying the principles they taught him, he adds.

Thompson credits many of his past life experiences with making specific contributions to his leadership capabilities. Service in the military taught him the value of structure, while travel opened his mind to different cultures and ways of doing things. Involvement in politics helped hone his leadership skills, especially in terms of interaction with other people, while hobbies developed his artistic side.

"Community service developed my humanity and an awareness of the need to give back," Thompson says. "Work influenced my financial perception and a sense of responsibility towards my employees and my community."

Thompson demonstrates business leadership in numerous areas. Externally, he has served on boards and been involved in other ways with a variety of business, civic and charitable organizations, including Kiwanis, Rotary, United Way, Habitat for Humanity and the Republican party. In the marketplace, he strives to position Image Magic as a leader in customer service and an early adopter of cutting-edge technology.

"Throughout life, I have had mentors and partners who have influenced my thinking."

Their efforts are paying off with higher employee retention rates and higher morale, which translate to increased productivity and a more enjoyable work environment, he says.

The Thompsons' business is part of a larger network, and the owners pride themselves on playing a leadership role in that context as well. "We have been a model for other business owners throughout the country in the processes we have developed for handling work flow, our internal human resources structure and our philosophy of the obligations we have towards our industry and our customers," Thompson says.

Chris Donner, a partner in Rock Solid Stone, an importer and distributor of granite, marble and other types of natural stone from around the world, credits two early-life experiences with helping to hone his leadership abilities.

The first was being taught by his parents the difference between right and wrong when he was very young. The second was his service in the U.S. Air Force and the years he subsequently spent overseas.

"The leadership role the United States plays in the rest of the world definitely influenced me and my way of thinking," Donner says.

For Donner, business leadership is all about example, a concept consultant Chapman says is critical to effective leadership.

"Leaders must motivate their employees in a positive direction," Donner asserts. "To do that, a leader must continually monitor his own behavior to make sure he is acting in a positive manner and that his actions are being perceived as such. That's not so easy to do at times. It's an ongoing process and needs constant evaluation."

Leadership involves challenges, in Donner's opinion, a major one being keeping the company pointed in a positive direction.

In a small business, especially, the demands of leadership also include assembling and retaining a team of reliable key people, establishing both short-term and long-term common goals and fostering effective communication among partners and associates.

"Communication is all important in leadership," he says. "If a leader cannot express himself effectively, he needs either to find a way to do so or find someone else who can. Without proper communication, a company can find itself moving in the wrong direction or in no direction at all."

When asked what played the defining role in his development of leadership characteristics, Brad Marks, vice president of I.W. Marks Jewelers, answers without a moment's hesitation: "That's easy; my father-being around him, seeing him do the things he does, his thoughts and beliefs."

Setting an example is a concept Chapman says is critical to effective leadership.

Among the many organizations on whose boards the elder Marks has served are the Houston Symphony, Greater Houston Better Business Bureau, Crimestoppers of Houston, the Society for the Performing Arts and the Cancer League of Houston.

"We do an awful lot in the community. We donate to dozens of charities and support all of the arts organizations and many other causes," says Brad Marks, who himself sits on the board of the Society for the Performing Arts. "If you are a leader, you have an obligation to step up and support these kinds of activities in your community."

Marks takes the leadership role he has inherited seriously, and it influences the decision-making process in many areas of his life, not just business. "It's always in the back of my mind," he says. "I approach every situation with at least some level of awareness that the decision I make can affect many people."

The greatest challenge-and the most important responsibility-of being a leader is the fact that you have so many people looking up to you, Marks says. "I have to set an example for our employees by doing the right thing. I have to be above board, do what is right and ethical in every situation, and I have to let them see that I am doing it."

The greatest challenge of being a leader is having so many people looking up to you.

Like most of his peers, Marks is convinced of the crucial role credible leadership plays in the success of any business. "It's very simple, really. If you don't have a leader, you're not going to succeed," he says. "It's like being Tracy McGrady on the Rockets. Every organization has to have a go-to guy." Abigail Tessorro, co-owner with her husband, Liam, of Gabby's Bottles & Brew traces her leadership roots to a positive early educational experience.

"My first grade teacher inspired me to read and learn as much as I could," she recalls. "She made a competition out of it. I read more books than anyone else in the class, and I have been reading ever since."

Although she didn't think of it in terms of leadership qualities at the time, that competitive edge instilled in her at a young age provided the foundation for a successful business career, including a 10-year stint with IBM Corp.

She left the corporate world in 2003 to move closer to her ailing father, launching her business in December of that year. In many respects, wine and spirits is a commodity business, and Tessorro knew she would have to find a way to create a leadership position in the marketplace for Gabby's Bottles & Brew if it were to succeed.

"I focus on making Gabby's the leader in customer service," she explains. "I sell the same products as all my competitors, and I needed something to set us apart. Customer service gets the job done."

Like Donner, Tessorro is a believer in leadership by example. She sets the bar high and applies the same standards in dealing with employees and customers.

"I believe the most important characteristics for a leader are fairness, honesty, respect and great communication," Tessorro says. "Communication is by far the most important and often the most challenging."

Sometimes being a leader means being an agent of change, and that's been a big part of the story of Dallas Pen Co., says Bobbie Melugin, vice president of the firm her father purchased from its founder more than 35 years ago.

The Dallas Pen Shop, as it was commonly known in its early days, was founded by Lyman Short as a fountain pen repair center and retail card shop in 1947. The widespread adoption of ballpoint pens in the ensuing years prodded Lyman to expand his assortment of writing instruments while cutting back on cards and repairs.

Melugin's father, Ed Melugin, joined the company as its first outside sales representative in 1955, tasked with calling on all the firm's commercial accounts and developing the wholesale side of the business.

Sometimes being a leader means being an agent of change in various ways.

For Dallas Pen, leadership means being out in front of emerging trends with the newest products and making sure its dealers benefit from the competitive edge in the marketplace that leadership provides.