The older the nation gets, the more we seem perplexed by our young people.

As we mark the 214th anniversary of the Declaration of Independence, the Times Mirror Center for the People and the Press has issued a report saying that today's 18- to- 30-year-olds know less, care less and vote less than any previous generation. The authors term this ''the age of indifference,'' adding that ''The ultimate irony is that the Information Age has spawned such an uninformed and uninvolved population.''

This is not the first time we have been given this message. Last November, People for the American Way released a study by pollster Peter D. Hart, focusing on 15- to-24-year-olds, which found they were ''turned off by politics and tuning out on citizen participation.'' Asked to describe a good citizen, few of those Hart interviewed suggested any civic involvement; only 12 percent even mentioned voting as part of the definition. Their teachers, in a parallel poll, agreed by a 2 to 1 margin that today's high school students have less interest in public affairs than their counterparts from the previous decade.

The consistency of these studies' findings clearly sends a warning signal about the failure of us older-generation Americans to impart to our children the importance many of us feel about the obligations and rewards of involvement in the community and nation.

But these studies don't capture all of the American reality either, as I was reminded this spring when I listened to the leaders of some of the major youth organizations, meeting under the auspices of the Council for the Advancement of Citizenship. Julian Dyke of the Boy Scouts of America, for example, said that membership in the Scouts has grown every year for the past 10 years, reaching 4.3 million -- one-third higher than it was in 1980.

So has emphasis on community service. Last year, he said, a ''Scouting for Food'' program, in which Scouts went door-to-door in their own communities, saw four million Scouts collect 72 million food items for distribution locally to homeless and needy people.

Others at the table contributed examples of volunteer youth programs, based in schools, churches and other community organizations, which have enlisted thousands of teens and even younger children in projects tackling civic needs.

''When you give them an opportunity, they respond,'' said Charles Tampio, vice president of Close-Up Foundation, which runs excellent Washington seminars for high schoolers. ''The key is for parents and teachers to realize that school is not preparation for citizenship, but rather that students are citizens.''

The Freedoms Foundation in Valley Forge promotes a ''Bill of Responsibilities'' that is the active counterpart to the Bill of Rights. Their message, said its director of youth programs, D. Susan Wallace, is that ''participatory citizenship is the price of freedom.''

Kathleen F. Kirby of the Constitutional Rights Foundation said its programs in East Los Angeles have demonstrated that ''the kids' volunteer activities are the best way to get the parents involved. The youngsters work on projects to help elderly people and newly arrived immigrants -- and they feel so good about it their families often 'adopt' those folks.''

But youth programs require adult leadership. Dyke, the Boy Scouts' director of public affairs, and Girl Scouts' president Betty F. Pillsbury, said that despite the increasing number of families where both parents work, they have no shortage of people willing to lead troops. Between them, the two organizations now have almost 2 million adult volunteers.

True, they have had to move with the times. The Boy Scouts put training materials for Scoutmasters on VCRs that can be watched at home and audio cassettes that can be played during car commutes. The Girl Scouts often divide troop leadership among four working women, with each taking responsibility for one meeting or Saturday outing a month.

And the programs also have moved with the times. Dyke sent me the 1990 edition of the Boy Scout Handbook. It is a far cry from the one I carried in my knapsack almost 50 years ago. Sure, there are still chapters on knot-tying and identifying trees by their leaves. But up front is a parents' guide to the serious problems of child abuse and drug abuse. And you can now win merit badges, not just for archery and woodwork, but for studies of American business, labor and diverse cultures, for citizenship in the community, the nation and the world, for consumer skills, environmental projects and handicap awareness.

In a pamphlet, ''Relating Traditional Values to Immediate Community Needs,'' Ben H. Love, the chief Scout executive, wrote: ''We must wholeheartedly accept our responsibility to protect the weak, the needy and the destitute. It is not a time to preach ideology, but a time to thwart the oppression brought about by illiteracy, hunger, unemployment, child abuse and drug abuse.''

The Scouts have programs going in all five areas. It's a sign that, whatever the statistics say, not all young people have given up on making this a better country.