By Tonya Vinas How successful a company's "top teams" are could lend insight into the longevity of its CEO, according to recent conclusions drawn from four years of research by Hay Group, Philadelphia. The professional services firm published its finding in the report "Top Teams -- Why Some Work and Some Don't: Five Things the Best CEOs Do to Create Outstanding Executive Teams." Interviewed were members of executive-level teams at leading global companies in the telecommunications, airlines, beverages, software and manufacturing sectors. In each case the team was led by a CEO or other executive decision-maker. "Average tenures of CEOs today are only about 18 months," says Hay Group Senior Vice President Debra Nunes. "Assembling, managing and leading a top executive team is increasingly seen as critical to both the CEO's success and the organization's. Given the increasingly important role of top teams, it's striking how many fall short of being truly effective." One of the foremost findings of the study is that leaders lack a concept of what a team is. Many CEOs mistakenly believe their top reports comprise a team. According to Hay, these groups may share information from each "silo" of business, but they are not collectively addressing a firm's biggest challenges and opportunities. "More importantly," the report says, "these groups lack the essential dynamics of a team, and are really no more than a periodic meeting of department heads who turn up to answer to the CEO." Among other things, Hay Group suggests that to improve top teams, CEOs become better listeners and rely on social skills "that are not always reinforced in a hierarchical corporate culture."