If you spend five minutes scrolling through your Facebook feed, you are bound to come across at least one post that promises to help you determine whether you are right- or left-brain dominant. The lateralization theory explains your thinking and behavior based on which hemisphere calls the shots: the left (making individuals more rational, logical, precise, and having a strong preference for dogs) or the right (edging others toward being intuitive, subjective, and creative, which apparently translates to a general avoidance of printed directions and a predilection for cats).
However, according to Stephen Kosslyn and G. Wayne Miller, authors of Top Brain, Bottom Brain, this idea is little more than "a dominant pop-culture story" which has never "stood up to careful scientific scrutiny." Recent work done by neuroscientists seems to indicate that both hemispheres of the brain work together in complicated processing tasks.
For example, where the left hemisphere is predominately responsible for discerning the sounds that comprise words, according to Carl Zimmer in an article for Discover magazine, "The right hemisphere is actually more sensitive to the emotional features of language, tuning in to the slow rhythms of speech that carry intonation and stress." If one area of the brain is compromised from injury or stroke, individuals may discern actual words but have a limited ability to understand the nuances that are part of verbal communication.
Despite a growing body of evidence that discredits lateralization, those of us who don't make our living as neuroscientists seem to prefer the somewhat romantic premise of left-brain vs. right-brain thinking. After all, it's both amusing and affirming. Because I prefer cats, feel compelled to create, and have been known to dissolve into tears when reading product manuals, lateralization validates both my career and lifestyle choices.
However fun and affirming, such binary thinking (I am either creative or not creative) can actually stunt our character development. For example, since the online test determined that I am 72 percent right brain, I might dismiss the need to develop my logical or objective skills because creative people don't need them (unless, of course, we want to make a living at what we do or put together an Ikea bookcase.)
Another unfortunate consequence of lateralization theory is that those who score low on right-brain dominance might assume the results are definitive. They want to create but apparently were not blessed with creative genes. Others breathe a sigh of relief because creativity spooks them. It's fine for the arts pastor, but they actually prefer that someone else do the messy and vulnerable work of creating. My husband (a writer/musician) and I (a writer and photographer) often hear others wistfully say, "I wish I could be creative!" To which we always respond, "But you are!"