Researchers at the University of Utah analyzed existing resting brain scans from 1,011 people aged seven to twenty-nine to test whether anyone relies more on one hemisphere overall.
Jared Nielsen and Jeff Anderson's team measured connection strength across more than 7,000 brain regions. Some individual regions were more connected on one side than the other, which was expected, but no one showed an overall pattern of stronger left-side or right-side network connections across the whole brain.
Specific functions do sit more on one side than the other. Language leans left in most people, and attention leans right, but that local pattern never added up to a whole-brain personality type. The idea had no imaging evidence behind it from the start, and this was one of the largest datasets used to test it directly.
Read the original study
Nielsen et al., PLoS ONE, 2013 · doi.org/10.1371/journal.pone.0071275
No one is a left-brain person.
Source
- Nielsen, J. A., Zielinski, B. A., Ferguson, M. A., Lainhart, J. E., & Anderson, J. S. (2013). An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging. PLoS ONE, 8(8), e71275. https://doi.org/10.1371/journal.pone.0071275