Early humans moved -- from the savanna to forests to mountains to islands, between hot and cold, from coasts and deserts and tundra and back again. We hunted, farmed and built increasingly larger communities, and then we left those places too.
Humans were nomadic throughout the length of the Stone Age -- and that represents 99% of our existence as a species.
Travel has clearly played a formative role in our evolution.
Our itinerant nature is also partly why our brains are so developed. When you're exposed to new experiences, your mental plasticity (rewiring, repairing) increases in a way that it doesn't when you stay in a circumscribed space and repeat the same behaviour day after day.
In contrast, while humans evolved on the go, our ape relatives tend to stay in one place. Even chimpanzees, which have a nomadic impulse, only roam within about a 60 square mile area.
Humans' "nomadic strategy meant that we were constantly confronting new environments," wrote learning expert Alison Gopnik in her book "The Gardener and the Carpenter," explaining the connection between travel and our species' brain development. "Wanderlust seems to be built into our genes."
Travel is change, and change makes you smarter because you must adapt -- whether it's to new ideas, new situations or new challenges. And when you successfully apply knowledge to how you live your life, that's the basic definition of wisdom. Our subspecies -- the only living heirs to those nomadic early human species -- is named homo sapien sapien. Sapien means "wise" and the double "sapien" labels us as double wise.
Want to max out the wisdom-inducing power of travel? Here are some experience-expanding parameters to impose on yourself the next time you leave home.
Don't go back to where you're already been
Sure, you love the places you love. But what about the places you'll love even more if you stop going back to the places you already love? You had to first go to those old places before you loved them, right?
The familiar brings comfort and some happiness (arguably less so when they become common). But the discovery of somewhere new and great brings learning and happiness. Write down all the places you've always wanted to go and let that inspiring list compete with the old places where you feel a gravitational pull. The new ones come with an added benefit of newly acquired wisdom.
Go as far as you can
The farther you go, the happier you'll be, according to researchers at Cornell University who analysed the language of tweets. They compared those written at work or home against those who shared their feelings while travelling far from either.
It intuitively makes sense. You're escaping your routine, your quotidian stressors, boredom. That's true of most vacations in general, but the added novelty of going far, far away -- Mongolia! Iceland! India! China! Australia! Thailand! Nepal! -- widens the cultural gap where all the great discoveries (internal and external) are made.
Go as long as you can
Money is always a limiting factor, as are available days off from work, but if you can swing it, the longer you are away, the deeper you'll engage with a place. If you could stay a month someplace you'd start to navigate it like a local, discover more details you love about it, and begin to make friends. This level of absorption takes willingness but also time.
Researchers at the University of Pittsburgh found that students who studied abroad were more likely to seek out and enjoy novel experiences (neophilia, it's called) in general, from tasting new foods to taking more risks. As the old Latin saying put it: Fortune favours the bold.
In his second memoir, "Love Life," the actor Rob Lowe recounted an entertaining story about commandeering a seaplane to sneak off a film set to watch a pro basketball game. Classic Lowe.
"Adventure is important in life," he then wrote. "To have a great life you need great memories. Grab any intriguing offer. Say 'yes' to a challenge and to the unknown. Be creative in adding drama and scope to your own life. Work at it, like a job."
Drama doesn't have to be danger. But don't forget you are the director and lead actor of your own film. Make it interesting. Make it one you want to replay for yourself and others.
"Following adventure creates stories that you keep forever," Lowe wisely added. "And anyone can do it."
Create a specific challenge
Travelling with some goal or mission -- from language immersion to cooking to volunteer work -- is a big share of the travel industry. But you can create your own quest. If you're a runner, map out an interesting route. Foodie? Track down the best meal at your destination by doing your homework but also asking people when you get there.
Or indulge in a more personally specific pursuit. I love scoping out coffee shops and bookstores in new places. I also love walking and running in cities that I don't know very well because I always discover something cool, usually a coffee shop or a bookstore.
I created a scavenger hunt for my family that we took on our last two big trips, to France and Yellowstone National Park. The list of items for us to find were subjective; they forced us to pay extra attention. They included items like "beauty," "kindness" and "love." And then we shared our treasures with each other.
Don't leave the details to others
Cruise ships, tour buses and all-inclusives have their upsides, but when you leave the planning, driving or explaining to others, you erase the value of figuring out where to stay and eat, what to see, and even what those sights mean. Convenience and even financial savings come at a different kind of cost.
Your travel experience will be deeper if you find great food and accommodations. Try reading about the local history of your destination from a book -- even fiction works. Figure out for yourself how to get from A to B. And enjoy meeting locals and fellow travellers.
Cruise ships and all-inclusives resorts make for good Instagram posts but terrible stories. Rob Lowe would probably agree.
Go on the road
Speaking of not leaving the work to others, a cross-country car trip should be on your travel bucket list. You choose the route, you find where to sleep and eat and you discover the places and attractions to cut into the monotony of the road.
I've driven across the United States four times and across Europe once, during which I've been to a museum devoted to "devil's rope" (aka barbed wire), had a close encounter with a tornado, skied in the middle of summer, took a selfie with a cardboard cutout of Bill Clinton at the Grand Canyon, talked for days to a pet fish, and got engaged to my wife.
You'll inevitably get lost, come up with some creative ideas while talking to your friend, fish or yourself, meet some strange people, and end up in some sketchy town or bar at some point. All of it makes for good stories.
But also get out of the car
Long journeys in cars or trains can be great for the soul, but they are never better than encounters with nature. You have to touch places, explore them. One study showed that creativity and problem-solving performance increased by 50% after subjects spent four days immersed in nature (note: without their smartphones). Again, it's the unfamiliar that fires up the synapses and stokes those flames of wisdom.
This is easy enough to accomplish. Route yourself through a national park or two. Scope out some hikes or swim holes before you leave. And buy a cheap tent so you can sleep outdoors at some point.
Get out of your comfort zone
Go someplace you don't speak the language and learn some of it there. Seek out local food and cultural experiences that you can't easily find at home. Learn the local public transportation. Don't have all the days planned out. Give yourself a fun goal when you arrive but also walk around without any agenda at all.
Mark Twain wrote that "travel is fatal to prejudice, bigotry and narrow-mindedness," in his travelogue "Innocents Abroad." And the positive effects of travel, he added, "cannot be acquired by vegetating in one little corner of the earth all one's lifetime."