Teenagers who feel they have a close relationship with their mother are likely to start having sex at a later age than those who don’t, according to an article published yesterday by the University’s Center for Adolescent Health and Development.

“There was this direct effect of closeness with mom,” said lead author Robert Blum, a University pediatrics professor.

Blum’s article meshes the results of two separate analyses of data from the National Longitudinal Study of Adolescent Health. It is the largest health-related study of adolescents in the United States, and documents interviews with more than 90,000 teenagers and their families.

One analysis looked at 2,000 of those interviews with 14-and 15-year-olds and examined differences between boys and girls. The other looked at 3,300 interviews with teens in eighth, ninth, 10th and 11th grades and compared differences among the varied ages.

Researchers interviewed the teenagers and their mothers twice individually. They asked how close teens feel to their mothers, how strongly teens feel their mothers care about them, and how well the teens communicate with their mothers.

During the first interview, the teenagers all said they had never had sex. In the second interview a year later, 11 percent of boys and 16 percent of girls reported having sex in the previous 12 months.

Blum said teens’ perceptions of how their parents view sex affect their decisions.

“Kids will pay attention to their parents’ values on sex,” Blum said. “But talk alone does not get the message through.”

Blum said parents can do other things to make a difference when their child starts having sex. The study suggests that getting to know their teenager’s friends – as well as their friends’ parents – can have an impact. So can holding high expectations for schoolwork, he added.

The studies specifically address mother-child relationships only. Some fathers were present for the parent interviews, but not enough to assemble conclusive findings.

Blum said any insight on how fathers factor in would be based on his experience as a father only, not from scientific data.

The article also said that when mothers reported their teenager was having sex, they were right 97 percent of the time. However, they were wrong nearly half the time when they reported their teenager was not having sex.

Dan Haugen welcomes comments at [email protected]