Only 56 percent of Houstonians over the age of 25 have attended any type of college, according to a new Portfolio.com study that places us at No. 121 of 200 metropolitan areas nationwide surveyed for the site's latest "U.S. Uncovered" brain power index.

The study, released this week, judged cities based on the medium income of all workers compared with the medium income of working people with five different levels of education, ranging from high-school drop outs to people with advanced degrees.

Let's hit you with some stats: The Houston metropolitan area contains 5.9 mllion people, only 9.5 percent of whom have earned a graduate or professional degree and only 18.4 percent of whom have a bachelor's. Nearly 20 percent dropped out before graduating high school.

To add to the same, two other Texas cities ranked even lower: McAllen-Edinburg at No. 199 and Brownsville at No. 198. Austin (No. 22) and even Dallas (No. 96) finished ahead of Houston.

We don't put a lot of stock in the study, though, for this reason: The city with the highest brain power index was Boulder, Colo. Eighty three percent of Boulder's adult residents attended some kind of college, and 26 percent — the highest record of the metropolitan areas surveyed — earned a graduate degree.

The survey didn't specify whether a master's of pot-smoking and frisbee golf affects brain power.