At the turn of the 20th century, the average life expectancy in the United States was just shy of 50 years. An American child born today, on the other hand, can expect to live to age 80. Indeed, a good number of us can reasonably expect to celebrate our 100th birthdays. But according to Dr. Robert N. Butler’s new book, The Longevity Revolution (PublicAffairs, $30), society is woefully unprepared to handle the consequences.

“For the first time in recorded history we are beginning to see the entire life cycle unfolding for a majority of the population in developed nations,” Butler writes. “The concept of old age itself is undergoing constant redefinition.” At one time, we assumed the last part of life was synonymous with disease and decline. Now, Butler notes, “the aging population in the past few decades is increasingly represented by vigorous, robust older people.” More than half of all Americans over the age of 85 report no significant disability whatsoever. Instead, these elderly pioneers are changing medicine, changing their communities, and voting in significant numbers—with large implications for the rest of us. 

Butler, a leader in the field of geriatrics and the president and CEO of the International Longevity Center, thinks the implications are generally positive. Despite the “greedy geezer” stereotype, he maintains that the old contribute as much to the young as the young contribute to the old. He coined the term “ageism” in 1968 to describe society’s prejudice against the elderly. In 1975, he wrote a Pulitzer Prize-winning book (titled Why Survive?) that explored how many older people were forced to endure poverty, abuse, and discrimination. As Butler admits in his latest book, things have gotten better since then. 

Rather than long retirements at the end of life, people might be better served by taking sabbaticals throughout their lives, says Butler.

The Longevity Revolution looks—in near encyclopedic fashion—at exactly why more of us are reaching old age, how we might live longer still, and how society can adapt to meet the needs of an aging population. Butler is at his best on his home turf: medicine. He packs fascinating details into a section on the science of aging. For instance, certain genetic mutations associated with shortness may also be associated with longer life spans. Women live longer than men, partly because they take better care of themselves, but also because the female immune system—geared up for gestation—may be programmed not to reject foreign bodies out of hand. Having two sets of X chromosome-linked genes may offer protection against life-shortening mutations. 

He also offers a few interesting societal prescriptions. The most debilitating diseases of old age aren’t necessarily the ones that kill you, Butler notes, which means that delaying their onset would be a major victory. For example, if researchers developed drugs or treatments that could delay Alzheimer’s disease by five years, that would reduce its incidence by 50 percent. “If dependency could be postponed by one month among all persons over sixty-five, we would save $5 billion per year,” he adds. If we want more old people to postpone retirement, we could delay the age at which people qualify for Social Security payments and simultaneously lower the Medicare-eligibility age. This would make older workers more attractive to employers, who wouldn’t have to pay for their health insurance. Rather than long retirements at the end of life, people might be better served by taking sabbaticals throughout their lives and continuing to work as their health allows. 

These are among Butler’s keener insights. Unfortunately, getting to them requires the reader to wade through 400 pages of other observations that are either pedestrian (we should study the need for more kneeling buses) or trite (“what damages the plankton at the bottom of the sea can damage us all”), or that represent liberal political views unrelated to aging and longevity (Butler urges us to “encourage public service through a mandated youth corps” and to “strengthen unions, since labor is the true basis of society and prosperity and to counterbalance the excesses of capital”). Some of Butler’s political comments are laughably untrue (for example: “there is less and less to differentiate the two major parties…. Both parties subscribe to a smaller role for government”). 

Perhaps, now past age 80, Butler simply decided to throw all of his ideas into one book. The result is a weighty, slightly tiresome read that, given Butler’s reputation for deep thinking, is surprisingly prosaic. Readers looking for a rehashing of liberal talking points (“among the thirty rich OECD nations, only four spend less [than the U.S.] on social programs as a share of the economy”) can wade through The Longevity Revolution. Everyone else would do better to just read the book jacket, since—the longevity revolution notwithstanding—our time on this planet is still limited. 

Laura Vanderkam is a writer living in New York City.