What's the greatest threat to the American family? The absence of a religious and spiritual foundation. That's the finding of a new poll by Better Homes and Gardens magazine, the third family study the magazine has conducted since 1972.
When the 200,000 respondents looked at family life in the abstract, 80 percent of them saw trouble, citing the need for a religious and spiritual foundation.
But when they looked at their own families, the picture became dramatically brighter. Kate Keating, managing editor of the magazine, sums it up this way: ''Although they face problems that are unique to the times, they also place a profound value on family life, and they work hard to make it successful.''
In a similar survey made by the magazine five years ago, inattentive parents were considered the primary threat to family life. In 1972, when the first such family study was conducted, 71 percent of respondents declared materialism to be the primary threat to family life.
One surprising finding of the survey is that conflicts between parents and teen-agers center more often on attitudes and behavior toward other family members, than on drugs, alcohol, or sex. Parents listed ''helping around the house'' as the second-most-frequent cause of conflict. Performance in school came in third. ''Respect for authority'' was listed by 15 percent of parents as a source of conflict.
An overwhelming 92 percent of parents responding to the survey said they were either very satisfied or mostly satisfied with the way their children are turning out.
Four-fifths of the parents of teens replied that they feel their teen-agers share their basic beliefs and values about marriage, family, sex, and religion. One mother added this note: ''In answering this questionnaire, my husband and I realized how lucky we are to have a teen-ager who is a 'good kid.' We sometimes focus too much on his irritating habits and not enough on the fact that he is not on drugs, drinking, or smoking. We thank you for this newfound insight.''
''Overall,'' says Ms. Keating, ''letters about teen-agers are distinctly more buoyant than were those we received five years ago. Then parents often told us they were having a rough time dealing with teen-age youngsters, communication was iffy, and despair just around the corner. The picture respondents paint today is vastly different.''
Teachers who five years ago were distraught over teen-age students' errant behavior and defiant attitudes also revealed a new outlook. One teacher commented: ''In our schools, I've seen a definite trend to the basics, not only in educational emphasis but also in the values, ideals, morals, and goals of our young people. They are willing to work hard and have a sense of fairness and honesty.'' Some teachers complained about drugs in the schools and discipline problems, but generally youngsters apparently are now held in higher esteem by their teachers than they have been in the recent past.
When asked what they would do if an elderly parent became incapable of living alone, more than one-third said they would open their home to the older family member. Nearly half would seek the assistance of a live-in helper. Only 22 percent approved of nursing-retirement homes.
Over half of the women in the respondents' families are employed outside of the home, with 36 percent of the married respondents indicating dual incomes are necessary to make ends meet. Yet more than two-thirds of all respondents said they believe working mothers have a detrimental effect on family life. They cited their observations of unhappy homes and uncared-for children, blaming the mother's absence.
Yet many working mothers reported that their children had developed a greater sense of personal and family responsibility without mom there to care for their every need.
Love is the primary reason three-fourths of the husbands and wives responding to the survey are staying together, but many pointed out that their love has developed over years of commitment to each other. A majority say their expectations of happiness in marriage are being met, and three-fourths have never seriously considered divorce.
As for the primary reason for marriages failing, most respondents listed ''immaturity of one or both spouses,'' followed closely by ''selfishness.''
When asked if a husband and wife must have children - either their own or adopted - to have a fulfilling and happy life, 83 percent answered ''No.'' Some couples pointed out that they simply cannot afford to have children. Others said they felt that couples who choose not to have children are missing something special. One mother, warning against self-centeredness in childless couples, commented, ''Children force us to expand beyond ourselves and our needs and develop within us a far broader outreach.''
Most parents remain convinced that they exert by far the greatest influence on their children's development. Television, viewed as second in its influence on children, was consistently seen as a negative and mesmerizing influence. Friends and teachers ranked third and fourth in the survey as influences on the young. Twelve percent of respondents listed the church as a great influence.
Only about half the respondents said they were satisfied with the amount of time they were able to spend with their children. One-fourth were definitely not satisfied, citing their own busy lives and those of their children as causes. Still, in most respondents' families, communication between parents and children was reported as ''good.''