I just got back from attending a funeral for my sister’s father-in-law. Pete was a jovial short-statured Italian-American, who lived to be 101 years old. He was actually born in Indiana, but spent his childhood back in Italy.

I mostly remember him from when he attended my mother’s funeral a few years ago. I was struck by how people were so attracted to his sunny disposition. His long life probably resulted from his positive outlook and good genes, as well as regular exercise from working in his large garden, his Mediterranean diet and bowling. Up until just recently, he still drove his own car, ate his own fresh vegetables and bowled every week. No one makes it past 100 without help, and Pete owed much of his independence to the constant support of my brother-in-law and a cousin who lived nearby.

There’s some longevity in my wife’s family, but such long lives are rare in mine, given our sedentary nature, volatile tempers, addictive tendencies and Polish sausage overconsumption. Busha, my paternal grandmother, was the only one on my father’s side to be long-lived. My mother always said it was because she was too mean to die. Busha was mean to virtually everyone. On holidays, she would give silver dollars to her favorite grandchildren, and nothing to other kids, hurting everyone’s feelings.

In 2007, the Hallmark company sold about 85,000 “Happy 100th Birthday!” cards and as of 2008, there were 96,548 documented centenarians in the United States. According to the International Longevity Center, by 2050, the number of American centenarians is expected to approach 1 million people.

Over the past 40 years, their numbers have increased tenfold. Currently, one in 50 women and one in 200 men reach that age. My wife says this shows who behave themselves and who doesn’t.

A recent article, in the British medical journal, “The Lancet,” predicted more than half of all babies born in industrialized nations since 2000, can expect to live longer than 100 years. American babies fare even better, with half of them born after 2007, likely to live to age 104.

I have told the story about how our kids, when they were preschoolers, argued over who could beat the other one up when they were a 100 years old. Maybe that wasn’t such a far-fetched fight after all.

At the funeral we attended, the priest said that a very long life can be both a privilege and a burden. People seem to have strong opinions about such longevity. According to an ABC/USA Today Poll, Americans on the average would like to live to be 87 years old. Only a quarter of people say they would care to live to be 100 or older and a majority of respondents say they have no interest in living to be 120, even if medical advances made such a thing possible. This is probably because two-thirds of them don’t trust that they could enjoy a good quality of life, like Pete. Some may feel that sacrifice has gone out of style and they aren’t sure they can count on their adult children.

The top concerns cited were poor health, being unable to care for yourself and loss of mental faculties. People were also worried about finances, being unable to drive and placing a burden on others. About half the people did not like the idea of being in a nursing home and not being able to work. Only about 20 percent, however, were concerned about losing their looks as they aged.

Increased longevity presents a variety of significant social challenges, according to gerontology researchers. Social scientists agreed that we are seeing a change in demographics that will fundamentally alter how society functions. As the population ages, there will be a significant increase in the number of disabled people who require care. In the future, we will need a larger skilled work force to support this older population. There also will be a much older group of caretakers within families. Like my brother-in-law, many people will find that much of their own retirement will be spent caring for aged relatives.

Social Security and retirement planning will need to be rethought, as people will work longer and need to support themselves for longer retirements.

On the positive side, as aging workers will have more technical, emotional and psychological experience, we may see a general increase in wisdom and productivity on the job. All this will require a dramatic shift from our youth obsessed culture and a return to the valuing of age and experience.

Longevity studies with the current cohort of centenarians show that people who were first borns were most likely to live to be 100. The father’s age does not appear to be significant, but having a young mother is very important to longevity. Living in the western part of the country and growing up on a farm are also among the strongest positive predictors of longevity. Having a father who was an immigrant, however, significantly lowers your chances for reaching 100. (Pete beat the odds on this one.)

Personality factors also play a role. According to Dr. Thomas T. Perls, the director of Boston University’s New England Centenarian Study, centenarians are often extroverted with many friends, strong ties to relatives and high self-esteem.

In his book “A Topical Approach to Life-Span Development,” John W. Santrock lists the five major factors important to longevity 1. heredity, 2. health habits, 3. education, 4. personality, and 5. lifestyle. Fortunately, most of these are things within our control to change.

To get an estimate of your current chances of living to be 100, you can visit Dr. Perls’ Web site (www.livingto100.com) and answer 40 questions about your health and family history. You will also receive a customized list of suggestions for improving your odds. My personal advice is 1. have a sense of humor, 2. start working in your garden, 3. lay off the Polish sausage, and 4. consider taking up bowling.

Terry L. Stawar, Ed.D., lives in Georgetown and is the CEO of LifeSpring, the mental health center in Jeffersonville. He can be reached at tstawar@lifespr.com. Check out his Welcome to Planet-Terry blog and podcast at http://planetterry.wordpress.com