Novel state intelligence quotient estimates, derived from the Scholastic Assessment Test, the American College Test, these tests combined, or the National Assessment of Educational Progress state scores, were not consisistently associated with state suicide rates. Validity checks pointed to possible methodological problems with state intelligence quotient estimates. Currently available estimates, therefore, do not seem appropriate to resolve the question of the direction of the ecological correlation of intelligence & suicide mortality across the United States. (30 refs.)