According to the 2011 Statistical Abstract of the United States, Massachusetts topped the nation with an average IQ of 105.6.
The ranking drew on education attainment, test scores (NAEP, SAT), and demographic factors. Massachusetts has long led in per-pupil spending, college graduation rates, and innovation economy (biotech, higher ed, tech).
Note: “Smartest state” is a media simplification—IQ estimates by state are controversial and methodologically debated. But by conventional metrics, MA consistently ranks #1.