Stereotype threat? Effects of inquiring about test takers' gender on   conceptual test performance in physics
  It has been found that activation of a stereotype, for example by indicating one's gender before a test, typically alters performance in a way consistent with the stereotype, an effect called "stereotype threat". On a standardized conceptual physics assessment, we found that asking test takers to indicate their gender right before taking the test did not deteriorate performance compared to an equivalent group who did not provide gender information. Although a statistically significant gender gap was present on the standardized test whether or not students indicated their gender, no gender gap was observed on the multiple-choice final exam students took, which included both quantitative and conceptual questions on similar topics. 
Alexandru Maries and Chandralekha Singh
physics.ed-ph