But they are exhibiting more recklessness in one respect: many more are drinking and driving.
The findings, which come in a new survey of top high-school students, give considerable comfort to those who still have faith in modern youth.
The survey showed that fewer young Americans today are having sex, but those who are use contraceptives more than before. When the survey was first conducted in 1971, 29 per cent of students said they had engaged in sex, with 52 per cent of those saying they used contraceptives. Last year 25 per cent said they had had sex, with 91 per cent of those saying they used contraception.
The survey of 3,177 students was sponsored by the publisher of Who's Who Among American High School Students, an annual publication that includes students aged 16 to 18 who have A and B average grades.
Questionnaires were sent to 8,000 of the 720,000 students in the 1993 edition and 3,177 replied.
The brightest 16 to 18-year-olds appear to be more cynical and adult than they were two decades ago. In 1971, 31 per cent of students who took part in the survey said they had a "great deal" of confidence in the president, and 26 per cent said they had a great deal of confidence in Congress. Today, those figures are 11 per cent and 9 per cent.
They are also disappointed in the mass media. Only 5 per cent said they had confidence in the media, down from 20 per cent in 1971. About half those replying said they would support some kind of censorship of televison and the movies, up from 36 per cent in 1974.
Drug use and smoking have declined considerably among the top high school students. In 1972, the survey's peak year for marijuana use, 27 per cent of students said they had tried the drug. This time, 10 per cent said they had. Those saying they used the drug regularly dropped from 8 per cent to 2 per cent.
Over the same period, students who said they smoked cigarettes fell from 11 per cent to 5 per cent.
But the survey showed a threefold increase in the numbers driving while under the influence of alcohol. In the new survey, 21 per cent said they had driven after drinking alcohol; in 1983, when the question was first asked, only 7 per cent said they had done so.
Nearly twice as many now think schools are unsafe. When the survey was first conducted in 1971, 7 per cent of the teenagers said school was dangerous. Now, 12 per cent believe schools are unsafe.
The survey reported that more students say they have considered suicide - up from 17 per cent in 1974 to 29 per cent now. More say they have cheated in their work, up from 70 per cent in 1983 to 78 per cent now. And more said they worried about being sexually assaulted or "date raped" by someone they knew.
The news from the family front is mixed, however. Divorce among parents has risen, but so has happiness in the home, up from 59 per cent in 1971 to 68 per cent today.