A girl is far more likely to become a teenage mum if she has a sister who has already become one, a new academic study shows.
“The research says how important family is compared to institutions,” says one of the researchers Professor Carol Propper.
The “peer effect” on girls aged 16 to 18, raised the chances of becoming a teenage mother from about one in five to two in five.
The researchers who conducted the study, said the effect was stronger when sisters were closer together in age, and also from poorer households.
The study concluded that the “peer effect” had a greater impact on teenage pregnancy than any education or advice they are given at school.
Prof Propper said: “Previous research has shown that family background and raising the education of girls decreases the chances of teenage pregnancy.
“However, these findings reveal the positive sibling effect still dwarfs the negative effect of education.
“These findings provide strong evidence that the contagious effect of teen motherhood in siblings is larger than the general effect of being better educated.
“This suggests that more policies aimed directly at decreasing teenage pregnancy may be needed in order to reduce teen births.”
Researchers studied census data of more than 42,000 Norwegian women, most of whom gave birth in the 1970s and 1980s.
The study, a collaboration with academics at Bergen University in Norway, the Norwegian School of Economics and Imperial College London, has been published as a working paper by Bristol University’s Centre for Market and Public Organisation.
The Labour Government’s £280 million Teenage Pregnancy Strategy aimed to cut the teenage pregnancy rate by 50 per cent in the years between 1998 and 2010.
However, last year, figures for 2008 showed that the teen pregnancy rate had only dropped by 13.3 per cent over the ten years from 1998.