One Head, Two Brains | Hidden Brain This week, we search for the answer to a deceptively simple question: why is the brain divided? Psychiatrist Iain McGilchrist explains why popular distinctions between the "left brain" and "right brain" aren't supported by research. He argues that one hemisphere has come to shape Western society — to our detriment.

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One Head, Two Brains: How The Brain's Hemispheres Shape The World We See

One Head, Two Brains

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Angela Hsieh/NPR
Illustration of the left and right hemispheres of the brain
Angela Hsieh/NPR

If you search for "left brain vs. right brain" on YouTube, it's not long before you'll find yourself in a vortex of weird claims and outlandish hype.

For decades, pop psychology books and web videos have made dramatic claims about people who are left-brained and people who are right-brained. It got to the point that many scientists felt they had to steer clear of the study of hemispheric differences.

Psychiatrist Iain McGilchrist experienced this pressure, but says he couldn't stay away from the field. He was too intrigued by a question that has fascinated philosophers and scientists for centuries: Why is the human brain divided in half? Iain answers that question in his book The Master and His Emissary: The Divided Brain and the Making of the Western World.

This week on Hidden Brain, we dive into Iain's research on how the left and right hemispheres shape our perceptions. Iain argues that differences in the brain — and Western society's preference for what one hemisphere has to offer — have had enormous effects on our lives.

Additional Resources:

The pieces of classical music included in this episode are:

Debussy's 'Doctor Gradus ad Parnassum'

The second movement of Bach's Double Violin Concerto

The Kyrie section of Bach's B Minor Mass

The final movement of Bach's Violin Concerto in A minor

Hidden Brain is hosted by Shankar Vedantam and produced by Jennifer Schmidt, Parth Shah, Rhaina Cohen, Laura Kwerel, and Thomas Lu. Our supervising producer is Tara Boyle. You can also follow us on Twitter @hiddenbrain, and listen for Hidden Brain stories each week on your local public radio station.