Obama's success isn't all good news for black Americans As Erin White watched the election results head towards victory for Barack Obama, she felt a burden lifting from her shoulders. 'In that one second, it was a validation for my whole race,' she recalls. 'I've always been an achiever,' says White, who is studying for an MBA at Vanderbilt University in Nashville, Tennessee. 'But there had always been these things in the back of my mind questioning whether I really can be who I want. It was like a shadow, following me around saying you can only go so far. Now it's like a barrier has been let down.' White's experience is what many psychologists had expected - that Obama would prove to be a powerful role model for African Americans. Some hoped his rise to prominence would have a big impact on white Americans, too, challenging those who still harbour racist sentiments. 'The traits that characterise him are very contradictory to the racial stereotypes that black people are aggressive and uneducated,' says Ashby Plant of Florida State University. 'He's very intelt and eloquent.' Sting in the tail Ashby Plant is one of a number of psychologists who seized on Obama's candidacy to test hypotheses about the power of role models. Their work is already starting to reveal how the 'Obama effect' is changing people's views and behaviour. Perhaps surprisingly, it is not all good news: there is a sting in the tail of the Obama effect. But first the good news. Barack Obama really is a positive role model for African Americans, and he was an impact even before he got to the White House. Indeed, the Obama effect can be surprisingly immediate and powerful, as Ray Friedman of Vanderbilt University and his colleagues discovered. They tested four separate groups at four key stages of Obama's presidential campaign. Each group consisted of around 120 s of similar age and education, and the test assessed their language skills. At two of these stages, when Obama's success was less than certain, the tests showed a clear difference between the scores of the white and black participants—an average of 12.1 out of 20, compared to 8.8, for example. When the Obama fever was at its height, however, the black participants performed much better. Those who had watched Obama's acceptance speech as the Democrats' presidential candidate performed just as well, on average, as the white subjects.After his election victory, this was true of all the black participants. Dramatic shift What can explain this dramatic shift? At the start of the test, the participants had to declare their race and were told their results would be used to assess their strengths and weaknesses. This should have primed the subjects with 'stereotype threat' – an anxiety that their results will confirm negative stereotypes, which has been shown to damage the performance of African Americans. Obama's successes seemed to act as a shield against this. 'We suspect they felt inspired and energised by his victory, so the stereotype threat wouldn't prove a distraction,' says Friedman. Lingering racism If the Obama effect is positive for African Americans, how is it affecting their white compatriots (同胞)? Is the experience of having a charismatic (有魅力的) black president modifying lingering racist attitudes? There is no easy way to measure racism directly instead psychologists assess what is known as 'implicit bias', using a computer-based test that measures how quickly people associate positive and negative words—such as 'love' or 'evil'—with photos of black or white faces. A similar test can also measure how quickly subjects associate stereotypical traits—such as athletic skills or mental ability—with a particular group. In a study that will appear in the Journal of Experimental Social Psychology, Plant's team tested 229 students during the height of the Obama fever. They found that implicit bias has fallen by as A．Excited. B．Victorious. C．Anxious. D．Relieved.