Variable agreement in Brazilian Portuguese is subject to social stigma, under strongly negative evaluation, brought to the public’s attention in 2011 in a heated nation-wide sociolinguistic debate triggered by TV Globo, the principal national television network. In order to isolate objective factors underlying this debate, we examine the variable ‘years of schooling’ in a trend study of Rio de Janeiro speech from 1980 and 2000. Analysis of relative weights and their corresponding ranges reveals that distance between effects of each level of education has increased over time. Polarization of the education variable in 1980 was moderate, while in 2000 polarization becomes extreme in an increasingly uneven social distribution of marked forms. The results reveal massive exacerbation of sociolinguistic apartheid, showing that nothing has changed in human interaction with respect to language despite many years of language studies. For this reason, we suggest that our sociolinguistic studies ought to trigger legal action, with creation of laws against linguistic prejudice, modeled on laws against other forms of prejudice, so that society can profit from results of sociolinguistic research in a humanistic and emancipatory way.