If you drew your own geography, what would it look like?

How many places do we really hold constant in our hearts at any time in our lifetime?

Maria Isabel Garcia

3:0:0am July 8, 2018

11:15:26pm July 9, 2018

How many places will you get to experience in your lifetime? I think if people had a choice, they would opt to always move around and experience different places. We make all kinds of decisions when going from one place to another, and for various reasons. It can be a restaurant, a park, a place of worship, your hometown, or a place you once discovered and find yourself visiting again and again. When I think about that and think about all 7 billion of us making those choices every day, I get stumped by the flutter of numbers that I sense are possible. But how many places do we really hold constant in our hearts at any time in our lifetime?

Apparently, not nearly as many as I thought. Scientists who have been studying human mobility in the past decade – made relatively easier because of mobile phones whose locations can be tracked – have arrived at a number and it is "about 25." The places are not the same, of course, since they change across one's lifetime, but apparently, regardless of time, humans generally move around 25 places.

Their recently published study struck me as one that is at the heart of human condition. This is because, first, despite technologies that enable us now to virtually experience a whole range of places, we would still choose to move physically. The study first tracked the places that 850 individuals frequented over a period of time. Later on, these expanded to 3 more studies that all in all accounted to 40,000 individuals around the world across time. They found that "about 25" is the total in a person's list, and that even if people drop an "old place/s" from their list, it gets replaced by another, thus retaining the number to about 25.

Second, this is surprising because some other studies on human behavior have always distinguished between "explorers" (the ones who choose to go to new places most of the time) and "exploiters" (the ones who prefer to visit the same places with "new eyes"). The study that hoists the "about 25" number puts into question that distinction, as it would appear that if "places you hold dear" is a field in the "human profile," the answer would still be about 25, regardless if you are an "explorer" or "exploiter." 

Third, this constant number of "about 25" is very intriguing, as it makes us ask if it is linked to other constant numbers that other studies on human behavior have found.

One of those numbers is tied to all the calling, texting, moving and "bonding" that we do. A study looked at the patterns involved in these 4 activities, and they found that to a high degree, population behavior could predict individual behavior. The study was able to predict as much as 71% when people will "call, text, move, and bond" and even higher (85%) when they will not do these things. This means that despite the seemingly chaotic rumble of human behavior, it can be highly predicted, which points to a more fundamental wiring – and thus, common ground – about us humans.

Another number is the more famous "150," which is the number of friends the human brain seems to be able to accommodate at any one time, i.e., in a stable manner. This is called the "Dunbar number" (because the researcher who arrived at this number is named Robin Dunbar). If we move around 25 places at any one time, do these places revolve around the 150 people we consider as friends? How many of those 25 places are also frequented by the "5" best friends who occupy the innermost circle of your personal "150"? How much of your 25 places are linked to the 150 friends you value? I have a hunch that our constant connection with other people is the primary shaper of the place maps we make for ourselves.

People generally have a bucket list of places they want to visit. My husband and I also made a list, but with a twist. It was not a list of places we wanted to visit, but a list of the things that we wanted to learn together. We listed about a dozen of them. One of the top things on our list was "evolution," which naturally brought us to many places – from the Galapagos, the Himalayas, to the Adirondacks – to trace the natural history of many things.

For a whole decade, it was a deliberate and joyful attempt to learn what we both considered were important for us to learn together. For those years, too, we had discussions with friends who shared the same passion. Whenever we found ourselves in town all at the same time, we'd meet at coffee shops and share our experiences, our conversations punctuated with laughter but always ending with a lot more questions than when we started. That made us continually tweak our list as we sharpened our own purpose.

When I think about that time in my life in light of the revelations of the recent study, I sense an image of our own private geography at that time – a constant shape and size, like the cream mark in the lattes I had in those coffee shops with my husband and our friends. We finished everything in our list by the time he passed away.

The people you are constantly with shapes and reshapes your brain, and they most likely play a deeper role in the 25 places you "inhabit" at any one time in your life. In other words, other people are your mapmakers. They shape your own personal geography.

How is your own personal geography shaping up? – Rappler.com

Maria Isabel Garcia is a science writer. She has written two books, "Science Solitaire" and "Twenty One Grams of Spirit and Seven Ounces of Desire." You can reach her at sciencesolitaire@gmail.com.