Third-smartest state in America: Nebraska The Cornhusker State knows a thing or two about raising a crop of kids who'll stay in school. Just 9.6% of Nebraska's residents lack high school degrees -- America's seventh-best showing. Some 71% of Nebraskan young adults also attend college (eighth place nationwide), while the state's high schoolers averaged 585 of the SAT math test -- also an eighth-place showing. (There are no figures available for TV watching among Cornhusker teens.) Martinez-Aleman says large Midwest states such as Nebraska have long had a tradition of "good sound public education." Still, the state's high average SAT math score probably benefited from the fact that just 5% of graduating students took the test this year.