Here’s some data from the WAIS-IV IQ tests about U.S. ethnic differences in IQ


Contrary to popular stereotypes, Asian Americans are not lopsided intellects who only outscore whites in mathematical or spatial ability, but actually outscore them in every index, including verbal.  Of course Asian Americans are not a representative sample of all Asians.

And contrary to the stereotype that whites are the most cognitively variable ethnic group, their full-scale IQs in this data-set actually show the smallest standard deviation of any U.S. ethnic group, though this could be be because Asian Americans are not a single race.

The scores above use U.S. norms, meaning 100 and 15 are scaled to be the mean and standard deviation for all Americans.  If we instead use white norms, (i.e. set the white mean and SD at 100 and 15 respectively), we find that  African Americans have a full-scale IQ of 83 (SD = 15.4), Hispanics score 87 (SD = 15.5), and Asian Americans average 103 (SD = 16.6).