What percentage of people are left-handed?

About 10.6% of people are left-handed, based on a 2020 meta-analysis covering 2.4 million people. The figure moves between 9% and 18% depending on how strictly you define it. Men are slightly more likely to be left-handed than women. Identical twins do not always share handedness, so genes are only part of the story.

Source: Papadatou-Pastou et al. (2020), Psychological Bulletin 146(6)