The way in which Darrell H. Mensel uses Arthur Jensen's 1969 research on IQ to assert that there are "measurable differences in cognitive abilities among racial groups" ("Racial differences," Forum, Tribune, Jan. 4) is nothing less than white supremacist dogma.
Dr. Jensen did observe differences in IQ scores and then erroneously attributed them to heredity and race. That most IQ tests have been shown to be racially biased is apparently an analysis too sophisticated for Mensel.
Mensel implies that the disappearance of the benefits of Head Start by the third grade is due to the limited cognitive capacity of minority groups. In fact, the 2012 Department of Health and Human Services study reported that while initial advantages in the cognitive domain were seen in Head Start children, non-Head Start children caught up by the third grade and that earlier studies point to benefits later in life such as high school completion and college attendance.