Humans are social creatures. We always have been and always will be. We are defined by our associations: spouses, family, friends. While the nature of those relationships may change some over time, their central role in our lives does not.

That’s why it’s a bit disturbing to realize that the percentage of Americans living alone is at an all-time high.

Nearly 30 percent of American households comprise a single person, a record high.

Scholars say living alone is not a trend so much as a transformation: Across much of the world, large numbers of people are living alone for the first time in recorded history.

“It’s just a stunning social change,” said Eric Klinenberg, a sociologist at New York University and author of the book “Going Solo.” “I came to see it as the biggest demographic change in the last century that we failed to recognize and take seriously.”

Homo sapiens is a social animal. Historians tapped ancient census rolls to show that our species has lived in groups for as long as such records have existed, stretching back at least to 1600.

The U.S. Census shows that “solitaries” made up 8 percent of all households in 1940. The share of solo households doubled to 18 percent in 1970 and more than tripled, to an estimated 29 percent, by 2022.

We know that humans have lived in groups a lot farther back than any census rolls go. The Agricultural Revolution gave rise to the first towns and cities, and that was 12,000 years ago. We have plenty of evidence that people lived in tribes and family groups before that. It’s our natural way of living.

So how is living alone affecting these Americans?

There are a number of pathologies associated with loneliness:

Loneliness has a wide range of negative effects on both physical and mental health, including:

• Alcohol and drug misuse
• Altered brain function
• Alzheimer’s disease progression
• Antisocial behavior
• Cardiovascular disease and stroke
• Decreased memory and learning
• Depression and suicide
• Increased stress levels
• Poor decision-making

(Hämmig O. Health risks associated with social isolation in general and in young, middle and old age [published correction appears in PLoS One. 2019 Aug 29;14(8):e0222124]. PLoS One. 2019;14(7):e0219663. doi:10.1371/journal.pone.0219663)

There is a big difference, though, between living alone in a close-packed neighborhood in a big city and living alone in a house out in the woods. One can live alone in an apartment in the city and still have meaningful, daily interactions with lots of different people. Someone living out on the end of a dirt road in a rural environment won’t have as many options.

But I think there is more to this than just the number of people you bump into or interact with throughout the day.

There’s more to social interaction than meeting people in public or at work. Living with someone means you share the most unguarded, intimate moments of your day with them. Those moments don’t have to be sexual, mind; they can be perfectly platonic, like with good friends living as roommates or parent/child relationships. It means having someone in your life that shares meals, shares chores, shares decisions, things you never do with colleagues or friends from outside your living arrangements. Those things go back to the very beginnings of people as social animals, and while I’m not a psychiatrist, nor do I play one on TV, I think they are vital to our mental health.

Now I’ll admit I’m kind of an odd man out here. When I was a young man and unattached, I preferred to live alone, and lived in some cheap places in order to do so. But at my age today (61), I am grateful, every day, to have my wife of 31 years to share my day-to-day life with.

Humans are social creatures. We always have been and always will be. This increasing trend of people living alone is troubling and begs the question: How many of the social pathologies we see today are due to this increasing isolation?

There’s no policy solution for this. The answer has to come from within us.