Left vs. Right Side Of Our Brain: The Relation to Human Intelligence

Posted by Peter Rudin on 17. May 2024 in Essay

Left vs. Right Brain       Credit:reatch.ch


The brain’s primary job is to process information and regulate body functionality. It receives information from the body through its senses of sight, touch, hearing, smell and taste. It uses that information to decide how to react to an external problem. As such the left and right sides of the brain focus on different roles. People who are especially skilled in one area of activity are often considered left or right brained. The thought behind this theory is that one side is stronger than the other. However, according to present day research this is not the case. Instead, each side is more or less responsible for certain roles or areas of focus. For example, the left side is generally responsible for logic and language, while the right is responsible for creativity and intuition. Exceptional skills result from the two hemispheres working together.

History of Brain Functionality and the Relationship to Intelligence

The left-brain-right-brain theory originated in the work of Roger W. Sperry, who was awarded the Nobel Prize in 1981. He studied brain functioning in patients who had their corpus callosum (the structure that connects the two hemispheres of the brain) surgically treated to battle epilepsy, for example. In the era of ancient Greece, reasoning, logic and the quest for knowledge were the markers of Intelligence, revered by philosophers such as Plato and Aristotle. In medieval times, faith was interwoven with intellect. Intelligence was not just a measure of knowledge but of morality and understanding of the divine. Then Renaissance followed where intelligence was seen as a canvas of artistic creativity and innovative thinking. As the age of Enlightenment dawned, rationality and empirical knowledge took the helm. Intelligence was a measure of critical, scientific thinking and by  the late 19th and early 20th centuries intelligence was something to be measured, tested and scored. It was a narrowly defined set of cognitive abilities represented by an intelligence quotient (IQ). Individuals such as Howard Gardner, Professor for Cognition at Harvard University, broadened this narrow definition. To them, intelligence was not a single thing to be measured but a multifaceted phenomenon that encompassed linguistics, mathematics, music as well as spatial and interpersonal skills. The view of intelligence widened to acknowledge the dynamic, adaptive nature of the human mind and its contribution to innovation. Today, many view intelligence less by the scores of an IQ test but more so by the ability to navigate, adapt and thrive in the ever-changing landscape of AI’s globalized digital world. Hence, for a human to create higher value based on brain activity, he or she must adapt by offering a more useful form of intelligence. 

Behavioural Aspects of Brain Functionality

According to the theory of left brain or right brain dominance, each side of the brain controls different types of thinking. In terms of behaviour, people are said to prefer one type of thinking over the other. Neither side of the brain is more or less intelligent than the other. They each focus on different roles, such as creativity or logic. Because individual brains develop differently the right side may perform a role that is typically the responsibility of the left side. To summarize:

Left Brain Behaviour

Science credits the left hemisphere with strong attention to detail and quantitative thinking. Some believe that some individuals are more logical and analytical because the left brain is dominant. However, this is not necessarily correct. For example, children considered gifted in mathematics, tend to have right and left hemispheres that work well together.

Right Brain Behaviour

Right-brained people might think more freely, qualitatively, and intuitively and are more interested in fundamental, global issues. Creativity and artistic abilities are often credited to right-brain dominance. A person who is right-brained,  is said to be more intuitive, thoughtful and objective.

Today, neuroscientists know that the two sides of the brain collaborate to perform a broad variety of tasks and that the two hemispheres communicate through the so-called corpus callosum. No matter how specialized the brain can get, the two sides still work together. Thanks to neuroplasticity, one’s brain can be trained to think differently, for example to be more intuitive and creative.

The Limits of Machine Intelligence

LLMs (Large Language Models), NLPs (Natural Language Processing Models), ML (Machine deep learning) models are flooding the market with applications such as computer vision or reinforcement learning that have been traditionally considered the foundation of human intelligence. Alongside this omnipresence of AI comes devaluation and commoditization. You probably will not get much of an advantage by using AI, but if you do not use it, you are likely to be at a competitive disadvantage with limited strategic value. To create more value, a human must adapt by offering a more useful output of his brain activity. AI and ML are really good at some things, such as image recognition but terrible at other things, such as intuition and judgement. The left hemisphere’s judgement represents both its strength and downfall. It narrows its view to a small window of things that can be pieced together logically. It assumes a complete understanding because it reduces problems to a set of logical pieces, yet it is blinded. It does not know what it does not know, and  It has a very narrow lens. It sees pieces and it cuts everything out that does not fit logically. In contrast, the right hemisphere, rich in broad perception, bears the weight of uncertainty. It knows that it does not  know, and this awareness produces outcomes that cannot be willed with the power of one’s mental capacity. In other words, AI solves things that can be well-defined, narrowed, and quantified. But it is blind to things that arise implicitly and indirectly and cannot be willed or dictated to apply wisdom, imagination, creativity, empathy, courage, humility, virtue, love, admiration, faith and understanding.

Forward Looking Research about Brain-Based Human Intelligence

Current research shows that the right side of the brain develops earlier than the left, leaving the left side more susceptible to environmental influences during development. Research also shows that it is healthy for the left and right hemispheres to develop differently, each with its own unique roles.

Genes and genetic mutations play a role in this healthy brain asymmetry and can change individuals suffering from autism, schizophrenia and other physical and mental problems. Additional research is necessary to improve the treatment of these health conditions. AI is good at things that the left hemisphere of our brain does but is really bad at things that the right hemisphere of our brain excels at. From experiments measuring brain activity with EEG (electroencephalogram), we know that the right brain hemisphere remains silent when throwing a glass onto the ground and watching it break. The details of that process are difficult to verbalize as it is difficult to explain mechanics rationally, but you can observe it effortlessly and apply meaning to it. Moreover, the right hemisphere is rich in its pursuit of depth, context and meaning. It is where the complexities of body language and facial expressions are understood and felt. Hence, the right hemisphere embraces uncertainty. It explores a myriad of possibilities and offers a comprehensive, holistic view of the world. It values individuals over abstractions and is where art, poetry, and music resonate with meaning. In contrast, the left hemisphere is rational, has language and believes itself capable of interpreting external events with total certainty even though it is less accurate than the right hemisphere. However, this brain asymmetry seems to validate its contribution to human intelligence.


Today’s AI aligns more with the needs of an expanding capitalistic society than it does with embodying the full spectrum of human capability. The essence of innate human skills and intelligence has, in some ways, been sidestepped and overshadowed by the pragmatic requirements of a world steered by commerce and growth. AI is a force that could recalibrate this imbalance if we use it as a servant rather than a foe. It can unlock dimensions of intelligence that have long been undervalued and bring back into balance a holistic view of the world, for example in medicine where a doctor looks at the patient as a whole for answers, not just his physical symptoms.

One Comment

  • Hello Peter,
    excellent essay as always, many thanks. Here same as in your last essay on VR your analysis and embedding in the wider context and timeline is very helpful, important for ones personal understanding.
    VR and AI are much interwound where I see (the mid) AR (Augmented Reality) with most practical progress and potential.
    Seems logical when understanding AR as the AI assisted reality. Last weeks Google I/O provided good information and indication on
    strategical importance and where the competition does further heat up with Microsoft Office 365 (OpenAI) and other major players.
    It is more a wordplay to tag features as AI, AR or AR stretched to VR. The more pragmatic tag ‘automation’ of someone working on, living, observing the digital evolution since the beginning (recall; people feared to become dump when the pocket calculators where introduced).
    The LLM’s as new key ingredients, now being bound to many existing services so to increase productivity, secure timelines, increase precision and quality.
    Here as you mention in the essay competitive companies can’t ignore it, ‘not use the pocket calculator’ ;).
    There are only two major players having the existing services, customer base, global spread and
    infrastructure to service companies of any size or personal usage; Google with Workspace and Microsoft Office 365. Their very large number of nodes to embed LLM / AI features also for 3rd parties via API/Web services (very large 3rd party developer base).
    In reference to your last essay VR (Meta story) will probably remain a niche market (Gaming, special trainings, simulators etc.). Side remark; some 20 years ago when I tried for some hours ‘Second Life’ advised also family members about this new ‘thing’, today they still joke to me when I’m not satisfied, to go to second life (despite never used it further ; ).

    Best greetings

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