For every man who fits into one of the categories of unmarried men put forth by social scientists  men who cannot commit, men who are afraid of divorce, men who have been forced to the edges of the economy  there is a man like Chris Cunningham of Staten Island.

Mr. Cunningham, 41, a sanitation worker, seems to defy any theory about why he is single. He has, he said, simply not met the right woman.

Born and raised in Brooklyn, and now assigned to an office job in Manhattan with the Department of Sanitation, Mr. Cunningham said he was undeterred by his parents’ divorce and was ready for marriage, having just ended a decade-long relationship going nowhere.

He makes a comfortable living at about $80,000 a year. He appears self-deprecating and sweet, and is clean-shaven (his head, too). Eager to have children of his own, he bought Christmas presents last year for several children in Milltown, N.J., where he often spends weekends with his best friend and neighboring couples.

With most of his friends paired off, and few single women in the Milltown clique, his dating life has stalled. “It’s funny,” he said one Saturday as adults mingled and children scampered with water toys at a block party. “You feel kind of like they met someone and got their lives started, and you’re still waiting for it to happen to you.”

Some social scientists have found that married men are healthier and earn slightly more than unmarried men. But it is unclear whether marriage produces higher incomes and better health, or whether people who are richer and healthier in the first place more often choose to marry.

Beyond the questions of finances and health, there is the issue of how content these men are. All the men interviewed for this article looked younger than their age. All said they were happy with their lives, even Mr. Cunningham, with his clear longing for a family of his own, and Mr. Thomas, of Fort Collins, who said he might move to Denver to meet more women.

Mr. Ryan, too, said he enjoyed being single. He stood talking in his kitchen on a Saturday when he had no plans other than a solo bike ride. It was a slow weekend day  his birthday, in fact  and though the phone never rang, he was free for dinner.