CAMBRIDGE: A leadership transition is scheduled in two major autocracies in 2012. Neither is likely to be a surprise. Xi Jinping is set to replace Hu Jintao as President in China, and, in Russia, Vladimir Putin has announced that he will reclaim the presidency from Dmitri Medvedev. Among the world's democracies, political outcomes this year are less predictable. Nicolas Sarkozy faces a difficult presidential re-election campaign in France, as does Barack Obama in the United States. In the 2008 US presidential election, the press told us that Obama won because he had “charisma” — the special power to inspire fascination and loyalty. If so, how can his re-election be uncertain just four years later? Can a leader lose his or her charisma? Does charisma originate in the individual, in that person's followers, or in the situation? Academic research points to all three. Charisma proves surprisingly hard to identify in advance. A recent survey concluded that “relatively little” is known about who charismatic leaders are. Dick Morris, an American political consultant, reports that in his experience, “charisma is the most elusive of political traits, because it doesn't exist in reality; only in our perception once a candidate has made it by hard work and good issues.” Similarly, the business press has described many a CEO as “charismatic” when things are going well, only to withdraw the label when profits fall. Political scientists have tried to create charisma scales that would predict votes or presidential ratings, but they have not proven fruitful. Among US presidents, John F. Kennedy is often described as charismatic, but obviously not for everyone, given that he failed to capture a majority of the popular vote, and his ratings varied during his presidency. Kennedy's successor, Lyndon Johnson, lamented that he lacked charisma. That was true of his relations with the public, but Johnson could be magnetic — even overwhelming — in personal contacts. One careful study of presidential rhetoric found that even such famous orators as Franklin Roosevelt and Ronald Reagan could not count on charisma to enact their programs. Charisma is more easily identified after the fact. In that sense, the concept is circular. It is like the old Chinese concept of the “mandate of heaven”: emperors were said to rule because they had it, and when they were overthrown, it was because they had lost it. But no one could predict when that would happen. Similarly, success is often used to prove — after the fact —that a modern political leader has charisma. It is much harder to use charisma to predict who will be a successful leader. Followers are more likely to attribute charisma to leaders when they feel a strong need for change, often in the context of a personal, organizational, or social crisis. For example, the British public did not regard Winston Churchill as a charismatic leader in 1939, but, a year later, his vision, confidence, and communication skills gave him charisma, given Britons' anxiety after the fall of France and the Dunkirk evacuation. And then, in 1945, after the public's focus had turned from winning the war to constructing a welfare state, Churchill was voted out of office. His charisma did not predict defeat; the change in followers' needs did. In practice, charisma is a vague synonym for “personal magnetism.” People vary in their ability to attract others, and their attraction depends partly on inherent traits, partly on learned skills, and partly on social context. Some dimensions of personal attraction, such as appearance and non-verbal communication, can be tested. Various studies show that people who are rated as attractive are treated more favorably than unattractive people. One study finds that a handsome man enjoys an edge over an ugly rival that is worth 6-8% of the vote. For women, the advantage is close to ten points. Non-verbal signals account for a major part of human communications, and simple experiments have shown that some people communicate non-verbally better than others. For example, a Princeton University study found that when people were shown images of two candidates in unfamiliar elections, they could predict the winners seven times out of ten. A similar study at Harvard, in which people were shown 10-second silent video clips of 58 elections, found that viewers' predictions explained 20% of the variation in the two-party vote — a more powerful variable than economic performance. Ironically, the predictions became poorer when the sound was turned on. In the 2008 election, Americans felt disillusioned by the Bush administration's war in Iraq, and by the financial crisis that erupted two months before the vote. Obama was an attractive young candidate who spoke well and projected a sense of hope for the future. Clearly, this is one reason why Obama gained a reputation for charisma. But part of his charisma was in the eyes of his followers. People sometimes say of charisma that “we know it when we see it,” but we are also looking in a mirror. As the economy worsened, unemployment rose, and Obama had to deal with the messy compromises of governing, the mirror became cloudier. Charisma tells us something about a candidate, but it tells us even more about ourselves, the mood of our country, and the types of change we desire. Hard economic times make it difficult to maintain charisma. Obama faces the continuing challenges of unemployment and a recalcitrant Republican opposition, and Sarkozy must contend with similar problems. When they are campaigning, however, their rhetoric will be freed from the need to compromise. This year's elections will be the true test of their charisma. Joseph S. Nye, Jr., is a professor at Harvard and the author of The Future of Power. This commentary is published by DAILY NEWS EGYPT in collaboration with Project Syndicate (www.project-syndicate.org).