STORY AND PHOTO BY KAREN BOSSICK

Sun Valley sports hundreds of engaged residents who take part in one or more groups ranging from the Sun Valley Bridge Club to Mountain Masters to the Wood River Women's Foundation.

And that's a good thing, according to a new film shown at last week's Sun Valley Film Festival.

Far too many Americans have been dropping out of organizations like the American Legion and various political groups. And Americans' choice to go it alone, rather than as part of a group, is causing divisiveness in society and loneliness at the personal level that could even spell a shorter lifespan.

That's the message behind "Join or Die," based on Harvard Professor Robert Putnam's groundbreaking research that led to the book "Bowling Alone."  Putnam's research chronicled the results of a half-century of Americans dropping out of civic organizations like PTAs and Rotary Clubs, book clubs and, yes, bowling teams. Conversely, a nation of joiners could address the polarity in the nation's political scene and other areas of life.

A move to rugged individualism has led to loneliness, fear and suspicion, contributing to divisiveness in society and, arguably, even a shorter lifespan, Putnam's research shows.

In the decades leading up to the 1960s, involvement was on the upswing, with organizations providing a place for Americans who might otherwise have felt left out, according to countless surveys Putnam made. The push to individualism may have begun deliberately in the 1970s to roll back the gains of the Civil Rights Movement and Women's Movement, theorizes Putnam.

Though a tidbit long, the film is fun to watch due to the perky insert of historical photos and videos. And the film directed by Pete Davis and Rebecca Davis, a senior director for NBC News for a decade, features Hillary Clinton, Pete Buttigieg and others.

"Our democracy needs us to be joiners," says Clinton.

Putnam, considered one of the nation's preeminent political scientists, was awarded the National Humanities Medal by President Barack Obama for his research.

Though a Republican, he said he was inspired to find a way to serve his country after watching John F. Kennedy tell his countrymen: "Ask not what your country can do for you--ask what you can do for your country."

"I felt as if he were speaking directly to me," Putnam said. "I realized: Bob Putnam, you have things to do for your country."

Putnam noticed that society was disintegrating as things began falling apart. More people were bowling than ever but not as many were in bowling leagues organized by such diverse groups as B'nai B'rith and Kiwanis clubs.

At the same time, his wife told him that there had been a sharp decline in PTA members and, it happened, there also was a decline in the membership of the League of Women's Voters and the NAACP.

Organized religion, which provided half of America's social capital, was in fast decline, as well.

"Though 9 in 10 Americans profess a belief in God, we're believing alone," Putnam said.

Putnam discovered:

* A 40 percent decline in number of Americans who attended even one public meeting on town or school affairs between the 1970s and the 1990s

* A 60 percent decline in the number of picnics Americans attended in that same time period

* A 50 percent decline in number of Americans who took a leadership role

* A 35 percent decline in church membership

*A 50 percent decline in number of Americans attending club meetings

*A 66 percent decline in those joining a union.

More Americans were spending more and more time watching TV, which is lethal for social connectivity, he added.

"He was naming a reality that everyone sensed but had not appreciated," said David Brooks, a conservative political and cultural commentator for the New York Times.

Areas where Americans are connected to one another, whether joining a football club or taking part in a civic group, provides social capital.

"The answer is clear," Putnam said. "Join or die. America's democracy depends on it."

Becoming part of something bigger means Americans are less likely to cheat or try to rob someone. If you cheat someone, those in your group are likely to find out about it so you're less likely to do it.

You can't have strong political institutions without strong social capital, said Buttitieg.

People don't have to return to the Odd Fellows Lodge or other organizations of their parents' and grandparents' time. But, perhaps, they can take part in community bike rides that have stops to survey art, historical sites or new community developments along the way, "Join or Die" offers.

Maybe they can join a church that is cultivating a garden to grow produce for the community.

"You can have the perfect educational model or the best possible economic scenario, but it doesn't work if people aren't participating," adds Putnam.

Want to host a screening of "Join or Die"? Visit putnamdoc.com.