Editor's note: This article appeared in the May 24, 2010, edition of Quirk's e-newsletter.

Over the course of the past 20 years, many things about how teens and tweens think have changed, including increased acceptance of homosexuality and decreased tolerance for abortion and premarital sex, according to a study conducted in 1989 and again in 2009 by Rochester, N.Y., research company Harris Interactive, on behalf of the Girl Scouts of the USA, New York.

While teen attitudes toward hot-button political issues of the 21st century have fluctuated greatly, there are some issues, like drugs, where the attitudes of tweens and teens have not changed much. The study shows just how quickly opinions on some deeply-held values can change. Are the changes good or bad? Well, that depends on your values and opinions.

One of the biggest changes found was that many more teens are accepting of gay and lesbian relationships and far fewer find them unacceptable than was the case in 1989. Most tweens and teens (59 percent) now feel that "gay or lesbian relations are OK, if that is the person's choice." This is a huge increase since 1989, when only 31 percent believed that "homosexual relations are OK, if that is the person's choice" (a slightly different question). Conversely only 30 percent of 7th-12th-graders now believe that gay and lesbian relationships are never acceptable because it is unnatural, compared to 56 percent who felt this way about homosexual relations 20 years ago.

A similarly massive change was found in response to another question about how a friendship would be affected "if you discover ... that a good friend ... of your own sex is involved in a gay or lesbian relationship." Twenty years ago, 40 percent said that the friendship would probably end; now only 14 percent say this. In 1989, only 12 percent felt that the "friendship would continue and not change at all." Now 48 percent feel this would happen.

Attitudes among youth about premarital sex also appear to have shifted. Preteens and teens today are more likely than 20 years ago to say they will insist on waiting until they are married to have sex (33 percent today vs. 24 percent in 1989). Also, fewer youth in this age bracket today say that sex before marriage is okay if a couple is in love (44 percent today vs. 53 percent in 1989). As youth age, they are more likely to agree that it is okay for a couple in love to have sex before marriage.

When asked what they would do if they were in a steady relationship for a long time, in love, and their boyfriend or girlfriend told them they were ready to have sex, more than one-third of preteens and teens said they would have sex in 1989, compared to 28 percent today. There are substantial gender splits at work here, with boys thinking that premarital sex is okay to a greater extent than girls. Given the above scenario, 38 percent of boys vs. only 18 percent of girls today say they would have sex, with older youth more likely to say this than their younger counterparts.

In a related note, there has been a modest drop in the minority of tweens and teens (25 percent) who believe that "abortion is all right, if having the baby will change your life plans in a way that you will find hard to live." In 1989, 33 percent felt this way.

The number of youth who feel that smoking "is OK" if the smoker "finds it enjoyable" has fallen from 27 percent to 18 percent since 1989.

Three-quarters (77 percent) of tweens and teens believe that "selling drugs is foolish because you might get caught," almost the same as the 80 percent who felt this way in 1989.

In questions not asked in 1989, most youth (78 percent) now believe that "everyone has to take care of the environment by doing things like recycling and using less electricity," and 59 percent of 7th - 12th graders believe that "being around people from different racial or ethnic background is important to me."

On some of these questions - smoking, premarital sex, selling drugs and taking care of the environment - there is virtually no difference between attitudes to teenage boys and girls. There are, however, some differences on other issues. Girls (59 percent) are much more likely than boys (38 percent) to believe that their friendship would not change if they discovered that "a good friend of yours of the same sex is involved in a gay or lesbian relationship." Similarly, girls (65 percent) are more likely than boys (54 percent) to believe that "gay or lesbian relations are OK if that is the person's choice." Girls (41 percent) are somewhat more likely than boys (33 percent) to believe that "sex before marriage is never right because it is a sin."

Youth response tends to vary according to age. Overall, younger youth tend to stick to the rules and have a stark sense of right and wrong. As youth get older, they see the world through more nuanced eyes and are more interested in testing boundaries. For example, older youth are more likely to say they will engage in behaviors like drinking and having premarital sex. Attitudes about abortion also change - as youth get older they are more likely to agree that abortion is justifiable. Only a quarter (25 percent) of 11-12-year-olds but a 58 percent majority of 16-17-year-olds believe "sex before marriage is OK if a couple loves each other." Those who believe that "abortion is all right, if having a baby will change your life plans" increases from only 18 percent of 11-12-year-olds to 31 percent of 16-17-year-olds. Those who believe that a friendship would not change if they discovered that a friend was gay or lesbian increases from 33 percent of 11-12-year-olds to a 55 percent majority of 16-17-year-olds.