It takes more than a gaudy economic boom to relieve Americans' unease about the country's social fabric. A national survey by Wirthlin Worldwide examines that anxiety as reflected in people's views on the strength of families these days. For starters, the shifting definitions and compositions of family have not weakened people's sense of its importance: 92 percent of respondents agreed with the statement, "Families stand at the center of our society. We can only go forward in this country if families and family values are strengthening." In that context, it's gloomy news that just 7 percent were willing to characterize "the state of the American family today" as "very strong and growing," with another 33 percent saying it's "reasonably strong." On the negative end of the spectrum, 27 percent said the family today is "not very strong," and 32 percent described it as "weak and losing ground." Why does the family find itself under siege? Respondents who said the institution isn't strong at present spread the blame widely, but their fingers pointed most accusingly at parents rather than at broader societal forces. Asked to cite "the major cause that has led to a decline in the state of the family today," they gave the highest number of votes to "parent's failure to discipline and teach respect" (12 percent). Next came "greater work demands on parents" and "parents' failure to teach children moral values" (11 percent apiece), with "increase in divorce rate" (9 percent) not far behind. Despite the current furor over marketing of R-rated movies to children, "entertainment influences" scored just3 percent of the tally. That put Hollywood marginally ahead of such factors as "materialism and selfishness in society" and "sexual permissiveness"(both 2 percent).