From this CNN story that we found at WPTZ, writer Mariano Castillo explains this phenomenon.
Although the birthrates of blacks and pardos -- the Brazilian term for mestizos, or people of mixed European and Native American heritage -- remain higher than for whites, experts don't cite that as the reason for the shift. Instead, they say that more Brazilians than ever are self-identifying as black or pardo, whereas in the past they would have checked off the box for "white."
"During this decade we have been noticing this increase in people declaring themselves black and pardo," Ana Saboia, a researcher at Brazilian Institute of Geography and Statistics, or IBGE, told CNN. The institute oversees the census.
In the most recent census, 7.5% of Brazilians identified themselves as black, and 43% pardo.
The trend is in line with a national public discussion of race that has raised self-consciousness, she said.
Brazil is enjoying a period of growth that, despite the global economic downturn, has pulled thousands of people out of poverty. The rising incomes may be helping to dispel and reject associations that exist in Brazilian society between poverty and skin color.
"In the past, people would have been ashamed to say, 'I am mestizo,' or 'I am black,' because of the link to poverty," Saboia said.
Read more: http://www.wptz.com/news/28257173/detail.html#ixzz1PXP9I2T0