And that clearly applies to the researchers (and anyone who buys their findings). Look. According to US gov't figures, in 1965, 51.9% of American men and 33.9% of American women smoked.  And no one was screaming at pregnant women not to, and "secondhand smoke" hadn't yet been invented.  Meaning one way or another, over half the babies born in 1965 were prenatally exposed to somebody's smoke. Nor are those percentages much different from the smoking rates of the parents of what later was known as The Greatest Generation.  The one that won WW2 and created an economic boom. Impaired as they must have been.

So what do you want to believe? Actual history or bizarre propaganda?

www.lungusa.org/.../Tobacco-Trend-Report.pdf