Where the Split-Brain Research Began

The whole left-brain, right-brain concept wasn’t always just a personality quiz you’d take at a corporate retreat. It came from some medical research back in the 1960s. Roger Sperry, a neuroscientist at the time, was working with epilepsy patients who had gone through a pretty extreme surgery – doctors had literally cut the connection between the two halves of their brains. His work ended up earning him a Nobel Prize, and the big reason for that was his discovery of some interesting differences in how each hemisphere processes information.

Sperry’s research revealed something interesting about how our brains divide up the work. The left hemisphere turned out to be much better at language and logical thinking, and the right hemisphere excelled at visual and spatial tasks. This wasn’t just theoretical speculation either. Sperry was able to see these differences firsthand in patients who had gone through split-brain surgery (where the two hemispheres are surgically separated). His findings changed our sense of how the brain works.

Over time, this research moved outside of medical journals and made its way into mainstream culture. Teachers became curious whether they’d figure out which hemisphere was dominant in their students to improve how well they learned in class. Business managers saw some promise in the concept as well – they thought figuring out how employees process information could help them build stronger, more tight-knit teams.

Self-help authors got on board too, recognizing a helpful framework that they’d use to help readers identify their natural strengths and see where they’d likely do well.

The theory resonated with many because it was easy to understand. Anyone could grasp the basic premise, and it gave them a clear explanation for why some are great at math, and others like to paint or write. It provided answers about human differences that felt satisfying – finally, a reason why we all work so differently and gravitate toward different careers. The concept caught on fast. Within a couple of decades, it had spread well beyond those original split-brain patients that Sperry studied in his research.

The theory took off partly because it seemed to validate what people were already experiencing in their day-to-day lives. Plenty of them do like analytical work, and others feel more pulled toward creative projects. A “left-brain” or “right-brain” label gave these preferences an official, scientific-sounding weight. The framework took what was actually a pretty complicated brain science and made it easy enough that just about anyone could use it to get to know themselves better.

Take Your Brain Test

Most personality assessments work in a pretty similar way. You’ll get a statement or a scenario, and then you choose how much you agree with it or how well it describes you. One question might say “I like to follow a schedule,” and you pick your answer from a scale – anything from strongly disagree to strongly agree. Some assessments take a different strategy and ask you to choose between two ways to do something.

The scoring system behind these assessments works in a fairly simple way. Every answer you choose carries a certain value, and each value leans toward either the analytical side or the creative side of your brain. Once you’ve completed the questions, the assessment tallies up your answers and converts everything into percentages. When you score 60% left-brained, most of your answers leaned toward logical and structured thinking (about 6 out of every 10 questions).

Your results change quite a bit if you take multiple tests, or if you retake the exact same one after a few weeks have gone by. Every assessment out there has its own set of questions, and they all score and weigh your answers a bit differently. How you feel on the day that you take it, along with what’s been going on in your life, can have a big effect on how you wind up answering some of the questions.

A genuine result depends on how you answer these questions based on what actually feels right to you – not what you think makes you sound better. Try to go through the assessment when you have enough time and you’re in a pretty calm headspace. As you go through each question, think about how you actually behave in your normal day-to-day life (at work, at home or wherever) – not how you wish you behaved or how you think you’re supposed to behave. One last point about these percentages – they show your natural tendencies at this point in time – not a permanent category that you’re locked into forever. You’re not bad at logic, and you can still do analytical work with a 70% right-brained score. When you’re looking at a choice between trusting your intuition or mapping everything out analytically, you’ll usually lean toward the gut feeling.

What the Research Really Shows

The left-brain versus right-brain idea has been around for decades, and it does seem to make plenty of sense when someone first hears about it. I can see why this concept became so popular. Modern brain imaging technology has revealed something quite different about how our brains actually work, though.

fMRI scans have given scientists a way to watch the brain as it works in real-time. These scans have shown us something interesting – the two hemispheres work together on almost everything we do. The corpus callosum is a thick bundle of nerve fibers that connects the two sides, and it lets information travel back and forth between them all the time.

We’ve all heard the claims that creative thinkers are right-brained or that humans only use 10% of their brain capacity. But neither one holds up when you look at the research. Modern brain imaging shows us that the two hemispheres of the brain light up at the same time when a person paints a picture or solves a math problem. Your entire brain stays active throughout the day, all day long.

One of the most interesting aspects of the human brain is its ability to rewire itself as time goes on. The scientific term for it is neuroplasticity, and it’s a big deal for how we learn and adapt. The neural connections in your brain can get stronger or weaker based on what you do and what you practice every day. The best news is that none of us is permanently stuck with just one way to process and take in information throughout our entire lives.

The whole left-brain, right-brain concept is a massive oversimplification of how our brains actually work. Your brain is a lot more complex than just two separate sides that each take care of different jobs. That said, the bigger conversation about different learning styles and the ways that we absorb information isn’t useless. Everyone has their own natural preferences for how they tackle problems and pick up new skills. Some of us lean more toward the analytical, and others are more creative and visual, and most of us land somewhere in the middle of that range.

Mental preferences are real, and they do shape how we process information and tackle different problems. We just can’t treat them like rigid boxes that define everything about how our minds work. The human brain is far more flexible and able to change than the old left-brain-right-brain model gives it credit for. Analytical and creative thinking don’t happen in separate, isolated areas – the two of them are active all over your brain at the same time, and they work together in some pretty complex ways.

Better Options for Your Mind

Thankfully, we have much better options available to us. Plenty of them have decades of research to back them up at this point, and they can give us a much more accurate picture of what our strengths are and where we do our best work.

The Big Five personality model is probably the most famous framework out there to get a sense of personality types. It measures you across five different core traits, and these five dimensions capture just about everything about your personality – if you’re the type of person who seeks out new experiences, how you like to talk to others, and your natural tendencies around organization. Each trait shows something different about how you behave, and it’s actually why this model can explain something as particular as why some people do their best work on teamwork and collaboration, and others do their absolute best work when they’re left alone to focus without any interruption.

Howard Gardner developed the Multiple Intelligences theory, and it changed how we talk about intelligence as a whole. His framework laid out the idea that one person could be exceptional at spatial reasoning and visualization, while another person has natural musical ability or a strong gift for reading others’ emotions. It opened up a much wider view of what intelligence can look like compared to the older model that just focused on verbal skills and how well you could work with numbers.

Cognitive ability tests are different. Personality assessments sort you into categories and types. But the cognitive tests measure how well you actually do on specific mental tasks. How well you remember information, your attention span, and your processing speed – these get evaluated, and you get a score for each one. What you get is data and concrete numbers about how your brain deals with the mental work that comes up in day-to-day life.

They all have their own strengths, and they can all help depending on what you’re looking for. The Big Five is great if you want to get a better sense of how you act in social settings or at work. The Multiple Intelligences theory helps you find talents and abilities that might not have been given much attention in a traditional school environment. Cognitive assessments measure specific mental abilities and give you concrete numbers on what you’re strong at. Personality frameworks like the MBTI are great to learn about your problem-solving preferences and how you connect with others.

Put Your Results to Good Use

Learning styles are a perfect example of this. Some learners absorb information much better when they can see it laid out visually with diagrams and charts. Grab a pen and sketch them out on paper if that sounds like your style, instead of trying to memorize everything straight from a textbook. Other learners need material organized in a very particular way before it all clicks for them. A numbered list with each step in a logical sequence is going to be a lot more helpful for that type of learner.

This applies to your work life, too. Project teams and collaborative work tend to do much better if you can match up team members with complementary strengths instead of everyone bringing identical skills to the table. A creative thinker who loves strategy and big-picture concepts will usually produce much better results with a detail-oriented partner who does well at execution and takes care of the follow-through on the smaller tasks.

Communication gets a whole lot easier if you keep these patterns in mind, too. Say that you have a coworker who responds best to logical explanations – you’d want to lead with the facts and sound reasoning if you talk to them. Or maybe your kid learns better if you present the information as a story with real context around it. Frame your lessons that way, and you’ll have much better luck with them. Picking up on how others actually take in information has the ability to adjust how you deliver the message without needing to change what you’re actually saying.

This applies to your career, too. It can help to point you toward fields where you’re more likely to do well. The way you absorb information and solve problems could be a solid indicator of which careers would feel like a natural fit for your style. This is a starting point, though. A quiz result shouldn’t become this rigid boundary that stops you from trying something different if it interests you.

The best part about learning all this is that you can use it to grow and develop your skills. You can then intentionally work on the areas that don’t come as easily to you. Say that you rely heavily on gut feelings and intuition – you can train yourself to think more analytically when the situation calls for it. Or if you lean heavily on logic and data, you might find it helpful to develop your more creative, intuitive side.

Your tendencies right now are just snapshots of where you are – not permanent limitations that define you forever.

What This All Means for You

The left-brain and right-brain model is a solid place to start if you want to get a better sense of your own strengths and preferences. Where it comes in useful is when you use it to pick up on patterns in how you work – the way you go about making decisions, how you show up in your relationships, and what strengths you bring to your job.

Self-awareness is probably one of the best skills anyone can work on, and it matters in your personal relationships and in your professional life. This awareness alone can change how you connect with others every day and creates a space for empathy and curiosity instead of judgment or frustration.

Our community gives you access to webinars, podcasts and blog content that will help you build on these skills in a way that feels relevant to your day-to-day work. When you join, you’ll be able to use our full on-demand library that includes training on HR topics and leadership development. Our webinar Pattern Thinking: Discover the Why Behind Your Choices looks at the patterns behind how you make decisions – don’t miss it!

We also highly recommend What’s My Style from HRDQstore. It’s a personality assessment tool that helps employees figure out their own working style and how to collaborate better with others who have different working styles. It gives employees strategies to adapt their style when they work with others who have a different personality type, and it tends to make everyone more productive regardless of their role in the company!