Earnest Shackleton led a daring expedition in 1914 to reach Antarctica. A year earlier, a lesser-known Canadian-led expedition headed in the other direction to explore the North Pole. Both ships, the Karluk in the north and the Endurance in the south, found themselves trapped by solid ice packs. Each crew was faced with a fight for survival. But the outcomes of the two expeditions couldn't have been more different.

In the north, the crew members from the Karluk, led by Vilhjalmur Stefansson, degenerated into a band of selfish, mean-spirited, cut-throat individualists, ending in the death of all 11 crew members. In the south, Shackleton's crew faced the same problems—cold, food shortages, stress, and anxiety—but his crew responded with teamwork, self-sacrifice, and astonishing good cheer.

In the end, each leader stayed true to his core leadership values. Stefansson valued success above caring for people. He consistently communicated his ultimate objective: getting to the North Pole. In Stefansson's words this meant "that even the lives of the [crew] are secondary to the accomplishment of the work!" To the very end, Stefansson denied that his drive for success led to a tragedy—for himself and his crew.

In sharp contrast, Shackleton's leadership focused on the value and dignity of his teammates. At one of the lowest points of his trip, Shackleton wrote, "The task was now to secure the safety of the party." The well-being of his team drove him to put others first. Shackleton even gave away his mittens and boots and volunteered for the longest night watches. By valuing each person, Shackleton forged a team that was willing to share their rations with each other, even on the brink of starvation. Through his example of sacrificial leadership, Shackleton was able to accomplish his ultimate objective: saving the lives of his crew members.