a 2002 study found an average of 18.6% european genetic contribution and 2.7% native american genetic contribution (with standard errors 1.5% and 1.4% respectively) in a sample of 232 african americans. meanwhile, in a sample of 187 european americans from state college, pennsylvania, there was an average of 0.7% west african genetic contribution and 3.2% native american genetic contribution (with standard errors 0.9% and 1.6% respectively). most of the non-european admixture was concentrated in 30% of the sample, with west african admixture ranging from 2 to 20%, with an average of 2.3%.