Experiments in biology that examine the existence of racial types seem to have been modulated by human rights movements from middle 20th century. In an attempt to acknowledge this hypothesis we will start our analysis in the 18th century, passing through the 19th century and finally briefly discussing the 20th century general situation. Thus, the present work has three main sections. In the first two sections, we will discuss the different forms races were classified and hierarchically ordered in the 19th century. In the third section, we will deal with 20th century problematic, dividing it in three sections. First, we will refer to racial classifications and hierarchical structuring in the first half of the 20th century. Then, we will mention the international human rights movement from mid 20th century that objected racial hierarchical structuring. Finally, some of the insights that tried to corroborate the existence of races derived from biology will be analyzed. The dissolution of the well versed hierarchy was of supreme importance for the associated social implications. But in spite of these efforts the persistence of racial thought is demonstrated in papers that during the last century tried to acknowledge human diversity.
Race; Classification; Hierarchy; Human rights; Genetics