Teen-agers are most likely to go to church regularly if their parents do, but it's the friends they make who most strongly influence whether young people take part in church youth programs designed for them.

These findings come from a new study on "Determinants of Church Attitudes and Participation Among High School Youth," conducted by Dean R. Hoge and Gregory H. Petrillo of the Boys Town Center at Catholic University.

The research by the two social scientists throws a little more light on the phenomenon of teen-age rebellion against religion. It also has revealed some interesting denominational differences in attitudes of youths from the three groups studied: Roman Catholic, Southern Baptist and United Methodist.

The three groups were chosen, the researchers say, because they represent the three largest religious groups in the United States.

Of the three communions, the Baptist youth retained the highest degree of religious interest and participation. Nevertheless, the Baptist youth studied joined their Catholic and Methodist counterparts in expressing a fair degree of cynicism and dissatisfaction with church programs.

Teen-agers from all three groups - the Catholics more than the other two - faulted the church for what they saw as hypocirsy of church members. Pollster George Gallup recently reported a similar finding in a nationwide survey of youth attitudes toward religion.

Of the groups surveyed, Catholics had the best church attendance records, with 55 per cent indicating that they attend church at least once a week. Baptists had 53 per cent while Methodists trailed with 35.

But at the same time, there appeared to be more discontent with their church among the Catholic youth than in the cases of the other two groups. Ten per cent of the Catholics surveyed complained that "the church's rules about morality are too restrictive for me." Five per cent of the Baptists and 3 per cent of the Methodists agreed with that statement.

Ten per cent of the Catholics also found their church "too narrowminded about modern religious thought."

Significant numbers of all three groups - 32 per cent of the Catholics, 34 per cent of Baptists and 25 per cent of the Methodists - agreed with the statement: "I have need for religion and interest in religion, but I cannot relate to the present church."

A like number - 7 per cent of Catholics and Methodists - but a smaller proportion of Baptists thought their church was "too cold and lifeless."

Only a tiny fraction of all three groups were willing to accuse their church of being "not really interested in bettering humanity."

While Catholics had the best church attendance record, Baptists and Methodists were more likely to participate in both church youth programs and religious retreats or camps.

Methodist youths were more likely than either of the other groups to have participated in religious youth groups outside their church, such as young life, Youth for Christ or charismatic groups.

Hoge and Petrillo acknowledge that their sample was drawn from largely upper middle class and largely white families.

The study, done in the summer of 1976, involved youngsters who had just finished the tenth grade and who were sons and daughters of members of 35 suburban Maryland churches.

There were 220 young people from each denomination in the orginal sample.

The authors point out that the study reflects "some bias, since the youths most alienated from the church refused more frequently than others" to answer the questionnaires.

Significantly, 32 per cent of the Catholic youths responding attended private or religious school. Yet they were more ready than their Protestant counterparts to criticize their church and, expect for weekly mass attendance, had considerably less involvement with their church than Baptist youth, of whom only 2 per cent attended non-public schools.

"Parents' church attendance is a very strong predictor of the youths' own church attendance, probably because the parents often take the youth to church," the authors say, adding, "Mothers' church attendance is a stronger influence than fathers church attendance."

The involvement of the parents in church affairs beyond Sunday morning worship also was found to have a pronounced influence on the teenagers. The amount of time spent by parents on church committees and the like "strongly predicts the youth group participation," the study said.

But while parental involvement in church activities themselves tends to draw their youngsters in, "they have little impact on youth's attitudes about the church and church youth programs," the study found.

Among teenagers, the attitudes and actions of friends their own age "are stronger determinants of participation (in church youth programs) than are family factors," according to the authors.

The Baptist youth, with 91 per cent, reflected the highest rate of assent to the statement: "I believe that God revealed himself to man in Jesus Christ." Eighty-one per cent of the Catholics and 79 per cent of the Methodists agreed to the basis statement of orthodox Christian belief.

The study found that "the main cause of disliking church youth programs are experiences of being snubbed or rejected by other youth participating and other unpleasant experiences in past religious training."