How many people really are left-handed? An international research team from Greece, the UK and Germany of which the biopsychology lab was a part now conducted the largest meta-analysis in the world on left-handedness to clarify this question. The researchers could show that prevalence of left-handedness lies between 9.3% to 18.1%, with the best overall estimate being 10.6%. Handedness variability depends on (a) study characteristics, namely year of publication and ways to measure and classify handedness, and (b) participant characteristics, namely sex and ancestry.

Papadatou-Pastou, M., Ntolka, E., Schmitz, J., Martin, M., Munafò, M. R., Ocklenburg, S., & Paracchini, S.. Human handedness: A meta-analysis. Psycho Bull. 2020 Jun; 146(6):481-524.