BOSTON (AP) _ The ''couch potato'' isn't flourishing on American soil.

While about 70 percent of U.S. adults indicate they watch some television during the evening, only 12 percent said it is their principal activity, according to a survey released Wednesday.

''We found that most people are not just simply couch potatoes, but do a number other things with their free time,'' said Carol Hess, research consultant for Lexington-based Decision Research Corp., which conducted the poll.

Most adults reported they combine television with other activities, such as cooking, cleaning and crafts, said Hess.

The survey, a follow-up to a previous leisure time poll released last year, asked 1,000 adults during October, November and December to describe how they spent the previous evening from 5 p.m. to 1 a.m.

After television, reading was the second-most popular activity, particularly among older respondents, with 22 percent reporting reading books or magazines as part of their evening.

Men comprised the majority of the 18 percent saying they worked during the evening, while the 9 percent reporting they shopped were mostly women, according to the survey. Twelve percent said they dined out.

Sports or exercising, going to a meeting or having sex each were noted by 2 percent of the respondents. One percent went to a movie.

''We had a lot of other responses from knitting to spent last night in jail to skinning a racoon,'' said Hess.

Only 15 percent rated their evening as ''great,'' with satisfaction higher among older or married respondents or people with annual incomes above $50,000.

The survey was launched after DRC researchers last year found that many respondents felt their leisure time was diminishing.

''We thought this was curious considering all the labor-saving equipment and that, in theory, people have a five-day work week,'' said Hess.

DRC research, however, indicates that people perceive they have less leisure time because of the trend toward highly structured activities outside of work, said Hess.

''When I ask you what your favorite leisure activities you might say sailing or something,'' she said. ''You are not likely to say you love going swimming at the health club five mornings a week, although that is something you chose to do. It's not a question that people have less leisure time. It's that people are losing their discretionary time; time that is for myself.''

Hess noted that the low percentage of inveterate ''couch potatoes'' suggest people are seeking to gain more control over their free time.

''I think we are looking here at people exercising more freedom of choice,'' said Hess. ''It shows they can exercise their discretionary power to pick what gives them pleasure rather than accepting what's out there in a passive way.''