As the U.S. population continues a pattern of rapid aging due to increased life expectancy and declining birth rates, another worrying trend is also occurring: a marked increase in loneliness, especially among older populations over age 45. Researchers say that there is a strong link between the uptick in loneliness and the choice that many Americans are making not to have children or to live alone apart from their adult children.

In an Institute for Family Studies (IFS) report published Tuesday, sociologist and author Rosemary Hopcroft notes that rates of loneliness are rising, affecting 40% of those age 45 and older (up 5% since 2018). In addition, she highlighted how the number of Americans living alone in their 80s and 90s will soon skyrocket, “from 6% of all households in 2018 to 12% in 2028.”

Data on younger generations indicate that the trend of solitary living is set to increase further as birth rates continue to plummet. IFS projections “show that as many as 30% of all women born in 1989 in the U.S. will likely remain childless.” As this childless cohort ages, studies show that they are more likely to report being lonely than those who have children. Hopcroft pointed to a study of Americans 50 and older showing that those “without living children reported a significantly higher level of loneliness compared to those with living children,” even when controlling for other loneliness-related factors.

But it’s not just older Americans without children who are reporting loneliness. Data suggests that even among those who do have adult children but live alone, about one-third (34%) report social isolation. The choice to live apart from their children may be driving this trend. Surveys show that almost a third (31%) of seniors say that they desire to live with their children when they can no longer live independently, but only about 17% actually live with their adult kids.

Experts like social scientist and Harvard professor Arthur Brooks say that when possible, seniors should live with their children and grandchildren for a host of beneficial reasons. He points to studies showing that if the arrangement is voluntary, “grandchildren raised in multigenerational households show higher cognitive functioning later in life than their counterparts from regular parent-child homes.”

Brooks goes on to argue that it’s the grandparents who may benefit the most from this arrangement. “Older people living in a multigenerational setting have a 40 percent lower mortality risk than those who don’t,” he writes. “They also report higher life satisfaction and lower depressive symptoms.”

As the share of childless women below age 45 continues to surge, research suggests that the voluntary decision to remain childless will likely prove to be shortsighted as they age. “The problem is that rates of loneliness are increasing among the old and are exacerbated by rising levels of childlessness, since the childless are more likely to be lonely in old age,” Hopcroft writes. “As fertility declines and life expectancy rises, more older adults will enter late life without children and with fewer built-in sources of intergenerational connection.”

Brooks personally attests to the value of intergenerational life, describing how he and his wife now live under the same roof as their 27-year-old son, wife, and children. “In a world so full of loneliness and dislocation, … [i]ntergenerational life and love are far more sweetly subversive than anything I ever tried as a young man. If you are ready to stand up to a world that leaves you cold, this might just be what you are looking for.”