Unrealistically small families portrayed in the hugely popular soapies seems to be the main factor in the effect put forward this month by researchers working for the London-based Center for Economic Policy Research (CEPR).
The fictional productions, made by top commercial network Globo, definitely have a "sizeable but not huge effect" on how many children Brazilian women want, one of the authors, Eliana La Ferrara of the CEPR and Italy's Bocconi University, told AFP.
Empirical analysis of census and other data showed the fertility rate drop in Brazil from 6.3 children per woman in 1960 to just 2.3 children in 2000 was partly the result of not just watching television, but specifically Globo's family dramas.
Women -- especially poorer ones with less access to other information -- exposed to Globo's soaps were deciding to cut down on the number of babies they wanted.
Imported Mexican soap operas shown on a rival channel did not have the same effect, the researchers found.
"We find that, after controlling for time varying controls and for time-invariant area characteristics, the presence of the Globo signal leads to significantly lower fertility," the study said.
As well as looking at previous research involving interviews with women, the CEPR team examined name choices for babies and found that mothers were four times more likely to name their offspring after a soapie character in Globo-watching areas.
Although celebrities influence name choices in other countries, the extent of the phenomenon in Brazil is "quite striking," La Ferrara said.
She explained that the impact of soap operas on a population's behaviour could have important implications for policy makers trying to institute changes in developing nations where literacy is relatively low.
HIV awareness, children's education and minority rights initiatives could all benefit, she said.
"Our work suggests that programs targeted to the culture of the local population have the potential of reaching an overwhelming amount of people at very low costs," she said.