Santa Cruz, Calif.

A SPATE of news reports have breathlessly announced that science can explain why adults have such trouble dealing with teenagers: adolescents possess “immature,” “undeveloped” brains that drive them to risky, obnoxious, parent-vexing behaviors. The latest example is a study out of Temple University that found that the “temporal gap between puberty, which impels adolescents toward thrill seeking, and the slow maturation of the cognitive-control system, which regulates these impulses, makes adolescence a time of heightened vulnerability for risky behavior.”

We know the rest of the script: Commentators brand teenagers as stupid, crazy, reckless, immature, irrational and even alien, then advocate tough curbs on youthful freedoms. Jay Giedd, who heads the brain imaging project at the National Institutes of Health, argues that the voting and drinking ages should be raised to 25. Deborah Yurgelun-Todd, a psychiatrist at Harvard Medical School, asks whether we should allow teenagers to be lifeguards or to enlist in the military. And state legislators around the country have proposed raising driving ages.

But the handful of experts and officials making these claims are themselves guilty of reckless overstatement. More responsible brain researchers — like Daniel Siegel of the University of California at Los Angeles and Kurt Fischer at Harvard’s Mind, Brain and Education Program — caution that scientists are just beginning to identify how systems in the brain work.

“People naturally want to use brain science to inform policy and practice, but our limited knowledge of the brain places extreme limits on that effort,” Dr. Siegel told me. “There can be no ‘brain-based education’ or ‘brain-based parenting’ at this early point in the history of neuroscience.”