in non-related individuals from Rio de Janeiro shows that it does not make any sense to put pretos and pardos in the same category". An autosomal genetic study of students in a school in the poor periphery of Rio de Janeiro found that the pardos among the students were found to be on average more than 40% European in ancestry. Before testing, the students identified (when asked) as ⅓ European, ⅓ African and ⅓ Native American. According to Edward Telles, three different systems related to "racial classification" along the White-Black continuum are used in Brazil. The first is the Census System, which distinguishes three categories: branco (White), pardo, and preto. The second is the popular social system that uses many different categories, including the ambiguous term moreno (literally meaning "tanned", "brunette", or "with an olive complexion"). The third is the Black movement, which distinguishes only two categories, summing up pardos and pretos ("blacks", lowercase) as negros ("Blacks", with capital initial), and putting all others as "whites". More recently, the term afrodescendente has been adopted for use, but it is restricted to very formal discourse, such as governmental or academic discussions, being viewed by some as a cultural imposition from the "politically correct speech" associated with the United States. Brazilian race/colour categories The first system referred by Telles is that of the Brazilian Institute of Geography and Statistics (IBGE). In the Census, respondents may identify their ethnicity or color from five categories: branca (white), parda (brown), preta (black), amarela (yellow) or indígena (indigenous). The term parda needs further explanation; it has been systematically used since the Census of 1940. In that census, people were asked for their "colour or race"; if the answer was not "White", "preta" (black), or "Yellow", interviewers were instructed to fill the "colour or race" box with a slash. These slashes were later summed up in the category pardo. In practice this means answers such as pardo, moreno, mulato, caboclo, etc., all indicating mixed race. In the following censuses, pardo was added as a category on its own, and included Amerindians. The latter were defined as a separate category only in 1991. It is a term for people of color who are lighter than blacks, and does not imply a black-white mixture, as there are some entirely indigenous persons. Telles' second system is that of popular classification. Two IBGE surveys made more than 20 years apart (the