Stephen Reicher, Alexander Haslam, John Turner and Michael Platow have collaborated on investigations into leadership and social identity culminating in their forthcoming book The New Psychology of Leadership.
They describe: 'When a shared social identity exits, individuals who can best represent that identity will have the most influence over the group's members and be the most effective leaders. That is, the best leaders are prototypical of the group - they not only seem to belong to but also exemplify what makes the group distinct from and superior to rival groups.
The most desirable traits and actions have to fit with the culture of the group being led and thus vary from group to group. Even some of the most oft-touted leadership traits, such as intelligence, can be called into question in some settings. Some people consider being down-to-earth or trust-worthy as more important than being brilliant, for instance. Where this is the case, being too clever may actually undermine one's credibility as a leader, as Bush's tactics suggest"
Full article in Scientific American Mind