Prior research suggests that top management team (TMT) diversity increases strategic innovation. We extended this argument to the case of entering new geographic areas. In addition to exploring the cognitive implications of TMT diversity, as done in prior research, we explored when diversity may lead to the formation of subgroups within TMTs hampering communication and the propensity to enter new geographic areas. We also examined how these positive cognitive and negative social implications change over time as TMT members interact over the years. The hypotheses were tested using ordinal probit analysis and data on 2,159 expansions of 25 companies over a period of more than three decades. Copyright © 2007 John Wiley & Sons, Ltd.