According to a Lifehacker article, believing you can be smarter makes you smarter. This is a helpful pointer for screwing with your brain and others.
Despite a lot of evidence to the contrary, many people believe that intelligence is fixed, and, moreover, that some racial and social groups are inherently smarter than others. Merely evoking these stereotypes about the intellectual inferiority of these groups (such as women and Blacks) is enough to harm the academic [performance] of members of these groups. Social psychologist Claude Steele and his collaborators (2002) have called this phenomenon “stereotype threat.”
Yet social psychologists Aronson, Fried, and Good (2001) have developed a possible antidote to stereotype threat. They taught African American and European American college students to think of intelligence as changeable, rather than fixed – a lesson that many psychological studies suggests is true. Students in a control group did not receive this message. Those students who learned about IQ’s malleability improved their grades more than did students who did not receive this message, and also saw academics as more important than did students in the control group.