If you're constantly daydreaming about traveling the world, rarely feel settled in one place, and get a case of the itchy feet regularly, you probably have wanderlust. But indulging in this urge to travel often takes up more resources than we may readily have available — for one, it's expensive, and for another, it's pretty inconvenient, requiring you to pick up your life for a few days and deal with the consequences of missing them. Obviously traveling is worth it, when you're able, but these inconveniences beg the question: why do we like to travel so much? Turns out that there's a scientific reason our suitcase is always half packed.
Wanderlust is strongly embedded in human evolutionary history. Modern humans, it's estimated, lived in nomadic communities for as much as 99 percent of our history, following the seasons, hunting, opportunities and ritual patterns. Sometime around 10,000 years ago, agriculture, aka the skill to harvest crops in one place that could feed bigger communities, was developed. The catch? You had to stay in that area to tend the things you were growing. Human settlements popped up, people stayed and had kids, and gradually villages became towns and then cities. But a nomadic urge isn't unnatural; if the situation in one place seems dire, it's always made good evolutionary sense to pack up and move on, even if in today's world you actually have rent to pay and a 9-to-5.
The feeling behind wanderlust doesn't necessarily have to do with the glamor of getting on a plane, though there isn't too much that's glamorous about air travel anymore. It's about novelty: seeing new places and new things. Human brains are acutely attuned to novelty and find it deeply pleasurable. We seek new and interesting things all the time, and our brain makes completely novel information "stand out." Various neurons have the specific job of finding novel things, and can distinguish between sights you've never seen before and stuff you saw once many years ago.
Why? Because curiosity and pleasure at discovering unfamiliar stuff are also a major evolutionary advantage. When you want to go to a place you've only ever seen in travel brochures, you're playing into an age-old reward system in your brain that gives you dopamine hits for new experiences that can help you understand the world around you. Thanks to a characteristic called neoteny, which means that we tend to act more child-like than other primates even when we're grown up, humans retain childlike curiosity and a desire to try new things into our adulthood. In many other species that tendency stops at maturity, if it exists at all.
Interestingly, a study in 2015 highlighted a genetic variant, DRD4-7R, that could be related to the desire to wander. It was immediately touted as "the wanderlust gene", but genetic reality is a lot more complicated; DRD4-7R appears to be tied to a greater likelihood for novelty-seeking behavior, impulsivity and adventurousness. Researchers hasten to point out that there isn't just one gene responsible for anybody's wanderlust tendencies, but some of the science behind DRD4-7R is very intriguing. It's an unproven hypothesis that migration in your past might make you more full of wanderlust now, but it's an interesting idea.
The flipside of the novelty coin is also fear of boredom. Humans hate boredom and will do a lot to get away from it. The poet Joseph Brodsky, in a commencement speech at Dartmouth College in 1989, told students, "Whether rich or poor, you will inevitably be afflicted by monotony. Potential haves, you’ll be bored with your work, your friends, your spouses, your lovers, the view from your window, the furniture or wallpaper in your room, your thoughts, yourselves. Accordingly, you’ll try to devise ways of escape [....] changing your job, residence, company, country, climate." The problem with that, Brodsky explained, was obvious: that you'll wake up eventually feeling the same sense of boredom and have to change everything all over again. Sometimes we experience wanderlust because we want to get away from the familiar, and travel represents the best way to do it.
If you're feeling the urge to pack up your life and run to somewhere else, there are good scientific reasons for that sensation, from a need for novelty to a potential genetic "push". Go get those new passport stamps.