Deborah Tolman, a professor of psychology at Hunter College in New York City and former director of the Center for Research on Gender and Sexuality at San Francisco State University, said that latest statistics did not surprise her.
But Tolman said the numbers were not as important as "what it means. ... Why are they making those choices and what kind of an experience is it?"
Tolman said that cultural attitudes about risky behaviors needed to be understood for prevention programs to work.
Non-Hispanic white females reported having oral sex more often (69 percent) than non-Hispanic black females (63 percent) or Hispanic females (59 percent).
"The differential in race and ethnicity is not biological," she said. "It's about meaning. Why do people choose different behaviors in different cultures?"
She also worried about the gender imbalance between "who gives and who gets" oral sex.
"In order to support safe decisions, we have to recognize the meaning of these behaviors and how heterosexual relationships are negotiated," said Tolman.
"Our girls need to know they are entitled to make a choice," she said. "They are engaging in behaviors out of various forms of pressure -- relationship and emotional pressure."
Psychologist Michaelson said the new report underscored the importance of sex education.
"What we are up against is everything these kids see in the movies and what their parents' comfort and discomfort is when they talk to them," he said. "In all the advertising, we say, 'Talk to your kids about drugs.' Where are the ads that say, 'Talk to your kids about sex'?"
Overall for adolescents, less than one-third -- 29 percent of females and 28 percent of males -- had had no sexual experience at all with the opposite sex, according to the report.
But those numbers might be misleading, according to Michaelson, who said adolescents are notorious for not speaking honestly about sex.
"There is also mythology and truth in high schools," he said. "Is everyone doing it? ... Some of my friends lied to me."