Study on risky behavior by teens and parents
From BBC News: "Teenagers are more likely to engage in underage sex if their parents smoke, drink or don't wear seatbelts in cars, a study suggests. Researchers in the United States [at Southwest Texas State University] have found a strong link between what they describe as risky behaviour by adults and teenage sex. They also believe there is a link between parents who smoke and drink heavily and children who get involved with drugs or crime." However, "The researchers found no evidence to suggest that risky behaviour by parents increased the chances of their children practising unsafe sex."