Jareau Hall breezed through high school in Syracuse, N.Y. Graduating in the top 20% of his class, he had been class president and a successful athlete, and he sang in gospel choir. He was actively recruited by Colgate University in rural New York, one of the nation's top liberal-arts colleges.

None of Colgate's recruiters mentioned to Mr. Hall that his combined math and verbal SAT scores were some 250 points below the class median—let alone that this would put him at great risk of academic difficulty.

Arriving at Colgate in 2002, he quickly found himself struggling in class, with far more rigorous coursework than he had ever faced. "Nobody told me what would be expected of me beforehand," recalls Mr. Hall, now 28. "I really didn't know what I was getting into. And it all made me feel as if I wasn't smart enough."

To make things worse, recalls Mr. Hall, "I was immediately stereotyped and put into a box because I was African-American. And that made it harder to perform…. There was a general feeling that all blacks on campus were there either because they were athletes or they came through a minority-recruitment program and might not really belong there." Shaken by the experience, Mr. Hall dropped out after his freshman year. He eventually returned to Colgate and graduated in 2007.