As we have seen, individuals often respond differently in a group context than they might if they were alone. Social psychologist Irving Janis (1972, 1989) examined group decision making among political experts and found that major blunders in U.S. history may be attributed to pressure toward group conformity. To describe this phenomenon, J ~ coined the term group think- the process by which members of a cohesive group arrive at a decision that many individual members privately believe is unwise. Why not speak up at the time? Members usually want to be "team players" They may not want to be the ones. who undermine the group's consensus or who challenge the group's leaders. Consequently, members often limit or withhold their opinions and focus on consensus rather than on exploring all of the options and determining the best course of action summarizes the dynamics and results of groupthink. The. tragic 2003 explosion of the space shuttle Columbia while preparing to land has been cited as an example of this process. During takeoff, a chunk of insulated . foam fell off the bipod ramp of the external fuel tank, striking and damaging the shuttle's left wing. Although some NASA engineers had previously raised concerns that hardened foam popping off the fuel tank could cause damage to the ceramic tiles protecting the shuttle, and although their concerns were again raised following Columbia's liftoff.these concerns were overruled by NASA officials prior to and during the flight (Glanz and Won~ 2003; Schwartz. 2003). One analyst subsequently, described the way that NASA dealt with these concerns as en example of "the ways that smart people working collectively can be di..nber than the sum of their brains" (Schwartz and Wald. 2003:WIG).