One reason why it's better to be a southpaw.

When we hear action verbs such as "hit" or "run," we understand what we've heard by activating a mental simulation of that action. In psychology, this is referred to as body-specificity hypothesis which has important implications that influence all of our daily lives. For example, market research has shown that consumers are more likely to purchase items that are placed in a way that's consistent with use. For example, seeing a mug in a shop activates the mental simulation of drinking from a mug. If the handle of that mug is pointing toward your dominant hand, then you are more likely to buy it than if the handle were pointing toward your non-dominant hand. Given that only 10% of the population is left-handed, we are constantly being exposed to images and media filled with right-handed people doing right-handed things. Since we know that mental simulation plays such a large role in learning, it begs the question of whether seeing right-handed actions in our environment creates an advantage for most people to live and learn in the world, while the lefties are disadvantaged. For example, when learning a new language, are we more likely to learn new vocabulary when seeing those words demonstrated by a person congruent with our own handed-ness.

Dr. Jaqueline de Nooijer of Erasmus University Rotterdam and her colleagues conducted a study asking whether left- and right-handed individuals learn words differently based on whether the word is presented with an action congruent with their handedness. More plainly, whether learning new words is influenced by the handedness of the student, and whether the word is demonstrated by a left- or right-handed image.

To do this, they used the Mechanical Turk to conduct 3 computer-based experiments to teach left- and right-handed participants action verbs from an artificial language called "Vimmi" (for example "luko" means "to pour"). For each word, the participant was shown the word, the definition, and an image demonstrating the meaning of the word. Each participant learned 6 new words with images from a left-handed perspective (a left hand pouring from a tea pot), 6 new words with images from a right-handed perspective (a right hand pouring from a tea pot), and 6 new words with images from a bimanual perspective (two hands typing on a keyboard). At the end of these learning trials, the participants took a test to see how many definitions they remembered. In the 1st experiment, 60 left- and 60 right-handed participants completed the study. In the 2nd experiment, another 60 left- and another 60 right-handed participants completed the study. In the 3rd experiment, another 120 participants completed the study. In each experiment, the "correct" definition for the words were re-assigned to new words, and the presentation of left vs. right perspective words was counterbalanced across participants.

They found that right-handed individuals consistently under-performed the left-handed participants in remembering words that were shown with a left-handed picture perspective. They also found that right- and left-handed participants did not differ in their memory for right-handed picture perspective trials. In experiment 1, left-handed participants performed equally well in bimanual picture perspective trials, while in experiment 2, left-handed participants far outperformed right-handed participants when learning bimanual terms.

In conclusion, lefties were better than righties when learning new words, despite living in a world organized to their disadvantage. But what does this mean? And who cares? Well, to me this is a lesson in how impressively adaptive our brains are. Left-handed individuals were forced by their environment to use more mental resources to convert information from their environment to behaviors they use everyday. In contrast, right-handed individuals didn't need to expel those resources, and perhaps they saved time, aggravation when using scissors, and elbow room at the dinner table, but at what expense to learning?

What can you do if you're a righty? Well, due to recent advances in neuroscience, we know that brain plasticity occurs throughout the lifespan. So, practice being ambidextrous this week, don't rely unnecessarily on your dominant side, and see whether you can make your left hand more useful to you. What should you do if you're a lefty? Go out and learn a new language, it may be easier for you than 90% of your friends.

de Nooijer, J. A., van Gog, T., Paas, F., & Zwaan, R. A. (2013). When Left Is Not Right Handedness Effects on Learning Object-Manipulation Words Using Pictures With Left-or Right-Handed First-Person Perspectives. Psychological science, 0956797613498908.