Is it racist to discuss inherent differences between black people and white?

There are many differences between people of African ancestry and those whose origins lie in Europe. Should these differences be hidden away and not spoken of, or is it acceptable to acknowledge them and discuss the possible implications? Kelly, Yvonne; Sacker, Amanda; Schoon, Ingrid; Nazroo, James (2006) Ethnic differences in achievement of developmental milestones by 9 months of age: the Millennium Cohort Study, Developmental Medicine & Child Neurology 2006, 48: 825–830.