Every day, as I took long walks through North Vancouver, I would think about the potential joys of a physically closer network. Wouldn’t it be great to have someone who could join me at a moment’s notice? How good would it be to have more non-scheduled hangs instead of ones that had to be planned weeks in advance?

This doesn’t have to be just a dream. Although technology is making it easier to maintain long-distance connections, nothing can replace seeing friends in person. Researchers have found that happiness spreads “like an emotional contagion (传染)”, especially among those who live close together.

Friends who live in the same city could decide to move within walking distance of one another—the same neighborhood, block, or even apartment building. Doing so would likely involve a lot of effort, but the resulting community could pay emotional dividends for years. Doing so would make it easier to support one another materially and emotionally.

Moving close to your friends requires some masterminding. Cities can make doing so easier by ending single-family zoning codes and encouraging a variety of housing types in neighborhoods. But even without official policies, people can make it work on their own. Sam Unger, 32, a food scientist and a friend of mine, has created a chosen family like this in Montreal, where about 15 of her friends live within walking distance of one another. When someone moves away, they try to transfer (移交) their lease (租约) to other friends. And when pals based elsewhere in the city are looking to move, Unger will try selling them on the positives of her neighborhood and sometimes even look for housing for them. “It’s funny,” she told me. “The other day, I bought a fire extinguisher, and she’s like, ‘Oh, well, I have one. You could just call me if you had a fire, and I’d be right over with it.’”