what never leaving your hometown does to your BRAIN

In the 2017 hit film Lady Bird, an ambitious Sacramento teen dreamed of leaving her hometown for the big city, only to grow homesick when she finally left. It cut to the conundrum that so many restless Americans face: Do I actually want to leave home? A study on American migration patterns published in PLOS One on Friday suggests that the answer is very often yes, but some people are more likely to leave than others.

Previous studies had already shown that Americans move from city to city several times over a lifetime, lead author and University College London mathematics Ph.D. student Rafael Prieto Curiel tells Inverse, but what we didn’t know is who they are and why they move. Those studies had assumed that people who do move are all equally likely to do so, but this study shows that this is not the case.

In the new paper, Prieto Curiel and co-author Steven Bishop, Ph.D., a professor of mathematics at UCL, show that people from cities with fewer than 100,000 inhabitants are twice as likely to leave home than those from cities with a population greater than 10 million, using US Census data and a new mathematical model. The size of both your hometown and the city you want to move to, they write, has a lot to do with the likelihood that you’ll actually leave.

Lady Bird thrift store scene
Lady Bird dreamed of leaving her hometown of Sacramento -- and she did. 

There are a number of reasons why people from small towns might be more likely to move. “It is possible that, through the many stages of life, it indicates a variety of factors,” Prieto Curiel says in an email. “For the young population, finding the right university; for the young adult, finding the right job; for the adults, finding the love of their life; and finally, for the mature population, a place for retiring.” People in big cities tend to have more options, so they have less reason to leave.

Where people from small cities go, however, is another story.

Who’s Moving Where

While American pop culture has glorified the idea of self-actualization in the big city — take Frank Sinatra “making it” in New York, or pretty much every storyline in Glee — it turns out that the people from small cities who move, generally move to cities that are about the same size or are smaller. The study suggests that a person from Tuscaloosa, Alabama (2017 population 100,287) might be more likely to move to Allen, Texas (population 100,685) than to, say, Los Angeles (population 3,999,759).

“Our findings show that, ignoring births and deaths and international migration, 80 percent of the movers went to a city with less population than their origin,” says Bishop in an email to Inverse. “For the most part, people prefer to stay as closely in size to what they already have. People don’t seem to like change.” Prieto Curiel says this finding was one of the paper’s “surprises” but offers a few ways to explain the phenomenon.

population density map 2010
Population density across America, as measured by the 2010 census.

Big cities, he says, are not only expensive but also polluted, full of traffic, and often far away from a person’s hometown. “Perhaps the life of a large city seems too stressful, too congested or many more negative attributes which are frequently associated with the lifestyle of large cities,” he says. However, he points out that this might be changing from one year to the next, as larger cities “offer more opportunities in terms of jobs, universities, research and development and more.”

When people from large cities do move, he says, they tend to move to larger cities, perhaps for similar reasons.

Where People Live Now

Current trends in American migration are in line with the findings of the new paper: People are moving, but they’re not moving to big cities.

In a 2017 analysis, FiveThirtyEight showed using US Census data that America’s smaller cities are growing much more quickly than their larger counterparts: “Population growth in big cities slowed for the fifth-straight year in 2016, according to new census data, while population growth accelerated in the more sprawling counties that surround them,” economist Jed Kolko wrote.

The new paper didn’t show that people were moving out of big cities per se, only that more people were moving to smaller ones. This was surprising to Bishop: “I would have personally expected that people were moving out of the big cities but there again I am older, my colleague Rafael would say the opposite,” he says.

Chicago Storm
Chicago was one of the slowest-growing metropolises in 2015-16, according to the US Census Bureau.

Where People Will Live Tomorrow

Both Prieto Curiel and Bishop are hesitant to make any predictions about the future based on their findings, as they are well aware that people’s behaviors can change quickly. Anything can happen in a city to prompt or prevent migration, says Prieto Curiel, who notes crime, terrorism, water stress, and droughts as possible factors.

Based solely on their results, however, it appears that in the next 50 to 100 years, large cities will continue to become more and more internationally diverse. Inter-city and international migration will also be more and more frequent, he says. Bishop adds: “based on our results our predictions would be that … a premier division of big cities would still exist.”

“Migration will become more and more frequent in the upcoming years as the costs of migration and of communication (so the psychic costs of migration) are reduced,” says Prieto Curiel, though he can’t predict how individual cities will grow. Maybe people will continue to move from small cities to other small cities until all the small cities are on par with New York and Los Angeles, he muses. Or perhaps trends will change, and migration to all cities will increase at the same rate, maintaining the “premier” division of big cities that exists now.

“There are certain patterns in the population which are maintained for many, perhaps hundreds of years,” he says. The desire to leave home, it seems, will continue to be one of them.