Investing in American Innovation Act of 2012 - Amends the Internal Revenue Code to: (1) extend through 2012 the tax credit for increasing research activities; (2) prohibit a reduction under any treaty of the United States of tax withholding for a tax deductible payment made between persons who are members of the same foreign controlled group of entities unless there would be a similar reduction for payments made directly to the foreign parent corporation of such entities; and (3) classify general aviation aircraft as seven-year property for purposes of the depreciation tax deduction (currently, expenses for aircraft can be deducted or expensed in the current taxable year). Defines "general aviation aircraft" as any airplane or helicopter not used in commercial or contract carrying of passengers or freight, but which primarily engages in the carrying of passengers.