Why do Lefties Exist?


I want you to imagine you’re writing in a notebook with a slow-to-dry pen. See anything wrong with that? If you answered, “no,” you’re probably right-handed. If you answered, “yes” chances are you are one of the 10% of people who are left-handed.


Alright righties, let me catch you up: because we write left to right, if you’re left-handed, when you write, the blade of your palm sweeps over the words you’ve just written. Therefore, if you’re writing with a slow-to-dry pen and you’re a lefty, you risk both smudging that which you have just written and getting ink all over your hand!


Lefties face other problems as well. Many scissors, bottle openers, and other tools of daily use are designed for the “normal” right-handed person. Thus, if you’re left-handed, and need to borrow someone else’s pair of scissors or bottle opener, there’s a 90% chance you’re out of luck. In short, the world isn’t designed for lefties.


Now I want you to imagine another scenario: a boxing match. Most boxers are accustomed to facing right-handed opponents. Therefore, when a lefty walks into the ring s/he has a distinct advantage over her/his less prepared opponent. The same holds true for a batter in baseball facing a left-handed pitcher, on the tennis court, and so on. So, I suppose, being left-handed does come with its advantages.


Now, let’s return to the key question: Why do lefties exist? Also, why are only 10% of people left-handed?


If you were really paying attention to the above examples, you may have noticed they fell into two separate classes. Writing (a form of communication) and using another person’s tools are examples of cooperative activities, whereas boxing, baseball, and tennis are examples of competitive activities!


In general, it’s beneficial to share dominant handedness with others under cooperative situations, from sharing tools, to carrying large objects, to handshakes, and beneficial to be a rarity with respect to dominant handedness, i.e. be a lefty, under competitive conditions, such as fighting. This was as true during human evolution as it is today.


So, some people are lefties because, while being right-handed is advantageous for cooperation, being left-handed is advantageous for competition (a fact that only holds when lefties are in the minority). Therefore, the number “10%” reflects an equilibrium between the respective push and pull advantages of being a slightly better cooperator or competitor.


Furthermore, this evolutionary observation allows us to infer conclusions about populations and even other species! Those in which the proportion of lefties is relatively greater place a greater relative importance on competition!


But even if you’re a lefty, it’s still your choice whether to extend a fighting fist or a helping hand. Just like Rocky, Gandhi was a southpaw.

Nicholas Norwitz

*The views and opinions expressed herein are those of the author and do not necessarily reflect the views of MDLingo.com, its affiliates, or its employees.