Jane Southwick and her twin brother Bill Abbott arrived in Hawaii on April 8, 1926, so unexpectedly that their parents had no idea a second baby was coming. A century later, the California siblings have just celebrated their 100th birthdays together, surrounded by children, grandchildren and great-grandchildren who gathered to mark the milestone.
The twins were born to Royal and Loreen Abbott while Royal was stationed in Hawaii with the U.S. Navy, according to reporting by Cleveland.com. Just weeks after they were born, the family traveled to New York, and according to family accounts relayed in that report, the twins were tucked into cabin drawers aboard the ship to serve as makeshift cribs during the voyage. From there, Jane and Bill grew up across Hawaii, Canada and several mainland U.S. locations before the family eventually settled in California, where the twins attended high school together.
A Century of Milestones, From Berkeley to World War II
Bill went on to serve aboard the battleship USS California during World War II, a ship with its own dramatic history. As detailed by the U.S. Department of War, the USS California was sunk during the December 7, 1941 attack on Pearl Harbor, then refloated and modernized before returning to combat for the Leyte Gulf and Okinawa campaigns, ultimately earning seven battle stars. Bill later flew patrol aircraft in the Navy Reserve for three decades before retiring from military service and working as an engineer for AT&T.
Jane's path took a more academic turn. She met her future husband, Ernie Southwick, while attending the University of California, Berkeley, and went on to earn a degree in child development, later working as a nursery school teacher. The couple raised five children together. Jane also became a published local historian, authoring a book about her Civil War-era great-grandfather and, in 2002, publishing a 112-page genealogical history through the Livermore-Amador Genealogical Society documenting early family history in California's Livermore-Amador Valley.
Health Struggles and a Family Pattern of Longevity
Reaching 100 hasn't come without hardship. Jane has dealt with pulmonary problems and a breast cancer diagnosis, while Bill has experienced a heart attack and kidney issues. Despite those setbacks, the twins remain active and engaged with family life, and the Cleveland.com report notes that their daily needs, appointments and errands are helped along by a family member named Nancy, who assists the siblings in staying independent.
Longevity runs deep in this family. Jane and Bill's parents lived into their mid-90s, and their older brother, Richard Abbott, died in 2025 just a month short of his own 103rd birthday. That pattern lines up with research from Boston University, which analyzed 1,500 families in the New England Centenarian Study and found that people who reach 100 are roughly nine times more likely to have a sibling who also reaches the century mark, with genetic factors exerting an increasingly strong pull on survival past age 90.
Rare Company Among a Growing Group
Twin siblings both reaching 100 is a genuinely rare occurrence, and Bill's presence among them is rarer still. U.S. Census Bureau data released in September 2025 found that centenarians remain overwhelmingly female, with women making up 78.8% of Americans aged 100 or older in 2020, even as the number of male centenarians grew by 85.3% between 2010 and 2020. Jane and Bill are part of a fast-expanding club nationally: the Census Bureau reported that the total U.S. centenarian population jumped 50% over that same decade, from 53,364 people to 80,139.
That growth is expected to accelerate. Pew Research Center analysis projects the number of U.S. centenarians will more than quadruple, from about 101,000 in 2024 to roughly 422,000 by 2054. California, where Jane and Bill have spent most of their adult lives, already leads the nation in total centenarian residents, according to demographic analysis from Northwell Health. Some researchers point to genetics as a major driver behind such longevity: a 2025 study using Danish and Swedish twin data estimated that intrinsic genetic factors account for roughly half of lifespan variation once external causes of death are controlled for.
For Jane and Bill, family and habit seem to matter just as much as biology. The twins credit staying active, close family ties and strong medical support for helping them reach 100, and their traditions continue at Jane's California home, which still hosts large holiday gatherings for children, grandchildren and great-grandchildren. As People reported, the twins have spent recent months reflecting on a century of family milestones, hardships and historic change, from a surprise birth in Hawaii to a life that has taken them, with relatives, to Alaska, Hawaii, Italy and several U.S. national parks.
