Jews as a group inherit higher verbal and mathematical intelligence with somewhat lower spikes in spatial intelligence than other ethnic groups. One observational basis for inferring that Jews have high intelligence is their prevalence in intellectually demanding fields. While only about 2% of the U.S. population is of full Jewish descent, 27% of United States Nobel prize winners in the 20th century, 25% of Fields Medal winners, 25% of ACM Turing Award winners, and 9 out of the 19 world chess champions. The average IQ score of Jews has been calculated to be 112–115