Our latest paper is out in Psychological Bulletin and report a collaboration with Marietta Papadatou-Pastou (National and Kapodistrian University of Athens) and Sebastian Ocklenburg (Ruhr University Bochum) with key contributions by lab member Judith Schmitz. We analysed hand preference
in more than 2 million people and found that left-handedness prevalence lies between 9.34% using the most stringent criterion of left-handedness, to 18.1% using the most lenient criterion of non-right-handedness, with the best overall estimate being 10.6%. But handedness is more complex than just left and right and as many as 9% of people use different hands for different tasks. All data and code available here.