Side Effects: How Left-Brain Right-Brain Differences Shape Everyday Behaviour

by Lorin J. Elias

Human behaviour is lopsided. When cradling a newborn child, most of us cradle the infant to the left. When kissing a lover, we tend to tilt our head to the right. Our brains influence our actions and habits more than we know.

248 pages, Kindle Edition

Published August 16, 2022

Reviews

[David Wineberg · Rating 4 out of 5]

Lateral prejudices are uniquely human. We differentiate between right and left in handedness, foot choice, eye preference and ear choice. We look at things funny when they go from right to left instead of left to right. Lighting in images needs to be from the upper left or we don’t like the image. To top it off, our brains are split into right and left hemispheres, and they cross over to control the opposite sides of our bodies. All these things and much more are explored in Side Effects, by Lorin Elias, a left-handed academic who has his own lab for testing it. He has made this his life’s passion, and it shows. It’s a fun rather than a deep read, even if it has its sloppy moments.

It is quite natural for a lefthander to be consciously aware of it at all times, if only because society has traditionally been so against it. Our languages damn things left and praise things right. Products continue to be designed without lefthanders in mind. Elias spends some time on this, collecting an enormous variety of slurs against his kind, but the book is mostly about unconscious choices. Things like which eye or nostril or ear are not anything anyone gives a thought to, but when studying the general population, people show certain preferences without knowing it or employing them consciously. Also practical observations like where people choose to sit in theaters and classrooms, and which way they look and how they hold babies are all aspects to study.

One simple example is asking people to walk down an empty hallway and come back. The majority will return by turning to the right. Why, you might ask? The answer is too mushy to be of use. I, on the other hand, ask what possible difference it makes. The answer to my question is that in a few circumstances, it actually can make a difference - that is not easy to find. But Elias certainly tries.

Statistically, lefthanders make up 10% of people. This does not appear to be reliably genetic, though it can somehow run in families. People can train themselves to change handedness, as has been a tradition in the Catholic church, which until recently worked hard to actually beat it out of children. In one famous case, tennis ace Rafael Nadal, a righty, trained to play tennis with his left hand (at his uncle’s insistence), and has never looked back. But overall, we still do not know the mechanism for handedness selection, a remarkable failure all by itself.

Handedness can show up in the womb, as most babies turn their heads to the right in utero before trying to do anything else. Again I ask so what, but there is no answer for me in the book.

About the only interesting outcome from nostril choice is that breathing in through the right triggers memories in the right hemisphere of the brain. Because unlike all other bodily functions, there is no crossover in the brain for smell. Smelling on the right is picked up by the right hemisphere, where memory is strongest. This has apparently been known for 5000 years, and yoga, which dwells on alternate nostril breathing, can demonstrate provable effects of it. But lefthanders do not generate old memories by smelling with the left nostril. The right nostril simply has different properties, a unique situation.

Most people, regardless of handedness, will cradle a baby with its head over their heart, seeming to understand that a heartbeat is soothing. It is natural for most primates, as shown in other species such as chimpanzees (though not as strongly in others such as orangutans). This even works with dolls. Unless the holder is a racist. White racists will cradle a black baby to the right instead of to the left, away from their heart.

Elias keeps harping on the division in the brain – right hemisphere vs left. He tries to position the “choice” of handedness and the other biases as somehow feeding a preference for one side of the brain or the other. But people don’t naturally know what the sections of their brains do. It is only really recently that we have garnered any clue to them at all. To say that choosing a seat in a theater or a classroom in order to favor the right hemisphere seems totally bogus on its face, and Elias does not prove, at least to my satisfaction, that there is anything in it. The best he comes up with is that people sit center right in order to give the left eye (and by extension the right hemisphere) a wider view of the rest of the room. Assuming they are left-eyed. It gets to be a little much.

On top of everything else, it seems that 20% of people have trouble differentiating left from right (as in: “No, the other left”), and women more than men. Left vs right is learned differentiation, and apparently there is not enough of a difference for many people to internalize it. But it can make a difference. Elias cites the example of surgeons removing the wrong organs or limbs, leading hospitals to have to draw on patients’ bodies exactly where the work is to be done. It doesn’t help that by convention, left and right are assigned according to the owner’s perspective, meaning those who look at the person need to remember that left and right are reversed from their own perspective. Unless the patient is lying face down.

On the other hand…

There are several anomalies even Elias does not appear to recognize, let alone connect and rationalize. One occurs in the predilection for showing the left cheek in portraits. He points to endless studies showing portraits, both paintings and photos, where people pose with their left cheek forward. He breaks it down to people thinking the left side of their face shows more emotion, while the right side shows more poise. Even Darwin recognized this. But is that what drives framing and composition?

There are just as many studies, it seems, to show that photos and paintings have an enormously strong tendency to be lit from the upper left. This leftward lighting bias colors thinking when it comes to picking out certain aspects in images. Humans are provably less comfortable when the light comes from a different angle. We expect the bowl of fruit to be lit from the upper left, and are less at ease with it if light comes from anywhere else. When producing their own images, people usually set light from the upper left themselves. But Elias never connects the two: that when images are lit from the left, it is much easier to pose the subject with the left cheek forward. The right cheek would have them waste the light on the back of their head. It’s not simply a handedness thing; it is contextual. But Elias doesn’t mention this.

Nor does he consider the rules. Painting, at least until modern art, had rules, lots of them. They had to compose and comprise geometric figures, for example. Anyone who broke the rules would not get commissioned for more like that. Maybe, just maybe, a thousand years of following the constrictions to art have caused people to expect more of the same, as if they were natural rules, even if the rules themselves have gone way. But the book makes no mention of artistic conventions.

There’s lots of reinforcement available: charts always spread right and up from the lower left, for example. Spreadsheets from the upper left, down. Flags are always portrayed as blowing in a westerly wind. In Westerns, (evil) Indians always attack from the left, while the “good” guys come from the right. It is pounded into viewers constantly, whether or not they even notice. But Elias never considers this factor. He continues to pursue the investigation on whether all this is innate, eventually finding it isn’t provable.

There are studies that take the same image and simply flip it, to see how people react to the difference. In one of Elias’ photo tests to prove left vs right preferences, a man is kissing a woman, tilting his head to the right to accommodate her. Apparently, most people kiss by tilting their heads to the right, but it is not a rule. (Now you will always be self-conscious over this. You’re welcome.) In the flipped version, he appears to be leaning left, and people don’t like that image as much. But in the flipped version, she is on the left and her head is now noticeably higher than his. So it appears that she is both dominating and kissing him from above left. Might it be that people are less comfortable with the apparently aggressive stance of the woman in the flipped version, and nothing whatever to do with which side their heads tilted to do it? This somehow occurs to no one, but it fairly screams the images are not equivalent, and the test is completely invalid. It is not proof of anything. Instead, the test concludes that kisses with heads tilted right are more passionate.

There’s also a segment of the book where people, particularly women, tend to hold living things (and dolls) in the left hand, putting the other being’s head close to the holder’s heart. There are all kinds of theories for Elias to dismiss over this, all based on this one observation. And it’s easy to see in real life if you care to look. But unfortunately, he backs it up with a photo of a supermodel, holding her teacup-sized dog up against her chest with her left hand, demonstrating how natural an action this is. But at the same time, she is signing autographs with her right hand. So maybe, just maybe I claim, she’s holding the dog on the left because she needs her right hand to write. This photo also proves nothing.

A third issue in the book is repetition. Elias keeps making the same points, referring to previous examples and observations as if they were new. At least three times, he explains that some cultures read right to left, while most others read left to right, and he lists the major RTL languages. This cultural difference can change how they read an image. But I feel quite comfortable saying readers will have got it the first time. I don’t know if this annoying repetition is an example of using the wrong side of the brain, but an editor could easily have remedied all of these things. And so as not to leave you hanging, RTL people do show some preferences that are opposite to LTR people, but not as many as you’d think. Many things are universal, or at very least, neutral –without a demonstrated side preference.

As to real world applications, there are a couple in the book. Because people tend to move right (at least in Western cultures), Elias says “We should be leveraging the results of these scientific studies to inform our design of public parks, museums, schools and shopping centres. We can even leverage the impact of these biases by strategically placing items within these spaces.” A note to marketers: We can “even place items, such as signs or products to the right if we want them to be noticed first.”

It also transpires that people tend to gesture with their right hands while speaking, and with their left when listening. Doesn’t matter if they’re right handed or not. Males do it more than females. This might be of use in knowing when to speak or how to keep others from speaking. Just something to notice.

And finally, there is sports. Lefthanders are prized, unlike in general life. A lefthander has a very different perspective of an opponent than a righty, whose expectations all seem to be that everyone is a righty too. In baseball, managers will change pitchers to deal with specific batters they feel will be fooled by pitches coming from the other arm. In tennis, the same confusion is often evident when a lefty plays a righty. Same for badminton. Using the “wrong” arm confuses opponents, making those players valuable. Elias focuses mostly on baseball, for the very good reason that it is compulsively obsessed with statistics. Every conceivable stat for every player has been saved somewhere, and laterality researchers like Elias can wallow in them endlessly.

For better or worse, laterality research is on the rise. Elias points to his book’s own references section, where the majority of studies come from this short century, overwhelming the work done in the past, even if Plato himself cast the first stone so long ago. Elias says he first laid out this book in 2004, but there was literally insufficient research to populate the chapters. There is now, but for the most part, it is merely interesting. For all the work that has gone into it, there are no hard or dramatic conclusions to point to, whether you’re a lefty or a righty.

David Wineberg

(Side Effects, Lorin Elias, September 2022)

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[Katie Murphy · Rating 3 out of 5]

This book was not what I expected. I have a background in medicine and psychology so I was ready to read about neuroscience. The research in this was SO detailed I was blown away. However, some of the studies and research shared didn’t hold my interest. I think this is a well written nonfiction book on this particular topic but be prepared for an in depth discussion

[Chris M. · Rating 4 out of 5]

It's a niche book that focuses on hand dominance and how it impacts the left and right-brain dynamic. It offers some explanations about the reasons why most of the population is right-handed. If you're interested in this topic, it's worth reading. If not, you might find it boring.

[Sarah · Rating 3 out of 5]

Listened as an audio book! 10/10

[Clivemichael · Rating 5 out of 5]

Fascinating, numerous lol moments. Quite enlightening and entertaining.

[Lisa Konet · Rating 5 out of 5]

I thought this was an interesting book about left brain vs right brain and how it makes us who we are. After reading this book, I found myself thinking about me being right handed but how with certain things I feel my comfortable with my left hand. An example, styling my hair. I am definitely a right handed with my writing by hand, although I try to strengthen my left hand.

I love the neuroscience in this book and how it relates to everyday life. That was detailed quite nicely. I was surprised how much I enjoyed this book and how much I learned.

Recommended if you like science and the human body.

Thanks to NetGalley, Lorin J Elias and Dundurn Pressn for an ARC in exchange for an honest review.

Available: 9/13/22