Bowling Alone: The Collapse and Revival of American Community, by Robert D. Putnam, Simon & amp; Schuster, 516 pages, $26. In 1954 my aunt and uncle, flush from rising wheat prices and an oil well, purchased a new Buick and joined the only form of entertainment within driving distance of their Kansas farm& amp; amp;mdash;a bowling league. They were part of a national trend. By the early 1960s, more than 8 percent of American men and 5 percent of American women had joined bowling leagues.But the nation's interest in bowling leagues soon passed. Fewer than 3 percent of Americans went bowling in leagues by 1998. My aunt, now a widow who lives alone, is too old to bowl. Her son, who lives 2,000 miles away, bowls alone if he bowls at all.For Robert Putnam, a professor at Harvard's Kennedy School of Government, the lonely bowler is emblematic of the serious collapse of community that has taken place over the past 30 years.Americans no longer spend as many evenings with their neighbors, less often join civic organizations like Kiwanis and the League of Women Voters, less frequently believe that other people are honest and trustworthy, and more and more adopt a private stance toward their religious convictions. Voter turnout, attending political rallies, working for political parties, and serving on local committees have all diminished markedly since the early 1970s. Many observers have commented on the rampant individualism that undermines Americans' community spirit. Indeed, polls show that a majority of Americans perceive the breakdown of community as a serious national problem. Yet most of the discussion about declining community consciousness has been conducted without benefit of solid evidence.Until now. Putnam has amassed ...