TRC Logo

Boston Globe, May 11, 2007

Sex, abstinence, and the adolescent brain

By Michael Craig Miller

GOVERNOR DEVAL PATRICK has proposed ending abstinence-only sex education in Massachusetts. It's smart policy. There is no evidence that abstinence-only programs work. A recent national study published in April showed that children who received abstinence-only instruction were as likely to have sex as students who didn't. Furthermore, access to accurate health information is a basic human right, even for adolescents. National surveys show a majority of adults and adolescents favoring comprehensive sex education.

It is also smart policy because it is consistent with what we know about how the human brain grows up.

Adolescence is a necessarily messy time. Risk is unavoidable. Detours in development are more common than straight lines. The job of adolescence is to move from dependence to independence, to explore limits, keep and break rules, and in many instances to rebel against the previous generation. Adolescents are also hot to explore their creativity, expand their talents, find meaning, and establish a value system.

Understanding the basic biology of brain development and learning can only help us help them become healthy adults.

Adolescents are already pretty smart by the time their hormones wake them up to sex. By 15 or 16, their intellectual development on many measures is equal to adults. But their emotional development lags. Their judgment is overwhelmed by their impulses and by peer pressure. Adolescents are much more likely than adults to take risks when they are with friends.

Changes in the brain account for the difference. Children have almost as many brain cells as adults, but those cells have much denser connections early in life. It's a time of less organization and huge potential for the brain. In response to the environment, for example, or feeling a parent's cuddling or hearing the English language, the brain prunes itself, cutting back on unnecessary connections, firming up the connections it finds useful. The transmission of signals gets even more efficient as an insulating substance called myelin covers the cells.

Throughout life, nerve connections are modified in this way. It's how we continue to adapt as adults. But the biggest changes occur in the first decades of life.

The brain doesn't mature all at once. The process of growing and pruning occurs in different regions at different times. The parts of the brain governing senses and movement develop first. The areas that govern complex functions mature later. The prefrontal cortex, which governs reasoning, doesn't start its growth spurt until preschool and most of the pruning is not accomplished until middle to late adolescence.

The last connections in the brain to mature are the pathways linking the emotional parts of the brain with the reasoning regions. Connections to and from the pleasure centers are also relatively weak, making it so much harder for many adolescents to resist sex.

How do we help them with this?

By providing them with sex education that their brains can grow on. Give them all the information they will need to establish healthy intimate relationships as adults. Don't narrow down options and shut out adolescents for whom abstinence is not a realistic choice.

Above all, comprehensive sex education should be versatile enough to take into account the jagged course of adolescent brain development. And it should be inviting enough to allow those teens who are in the greatest developmental turmoil to stay engaged.

As a good math or English teacher does, encourage students to bring in their problems and get help working them through. Expect them to learn from their experiences and their mistakes.

It will be good for their brains.

Michael Craig Miller is the editor-in-chief of the Harvard Mental Health Letter.

Send this page to a friend!

Home   About Us   Newsletters   News Archives   Donate