*2.1. Sample*

The participants were visitors to an interactive, three-month public engagemen<sup>t</sup> and citizen science collaboration project called Me, Human (www.mehuman.io/, accessed on 10 February 2021) hosted by Live Science at the London Science Museum between 02/07/2019 and 31/09/2019. Me, Human consisted of a series of experiments exploring motor-sensory behavioural biases and cognitive ability. Experiments included measurements of grip strength, dexterity, cognitive puzzles, and functional brain laterality, in which participants could engage in as many of the experiments as they wanted. Volunteer participants first completed a baseline demographic questionnaire, including date of birth, sex, and handedness for writing (our hand asymmetry indicator), before engaging in the experiment(s). More than 1600 individuals participated in the Me, Human experiments, of which n = 1286 took part in the 'Get a grip' experiment that measured grip strength and hand size, and collected further information about lifestyle and daily activities using the hands. Within this sample, 719 were classified as 'adults' between the ages 17–83 years old because the hand is fully developed (i.e., complete fusion of hand bones) by 17 years of age [80,81]. The remainder of the sample (n = 567) were children and adolescents (6–16 year-olds), and were excluded from this study. Of the total adult sample, 57 participants were removed from the data set due to incomplete data or because they had a recorded hand and/or arm injury within one year of the testing date, making the final sample size n = 662. Of the

662 participants, 89.6% (N = 593) self-reported as right-handed, 9.0% (N = 60) left-handed, and 1.4% (N = 9) as ambidextrous. Participants self-reported as ambidextrous were excluded from subsequent analyses, with the remaining sample containing 653 participants (Table 1; Figure S1). Our sample was divided into 10 age categories (Table 1) of five-year intervals, excluding the first (17–19 years) and last (60 years and older) age categories.


**Table 1.** Sample used in the analyses with details on the number of participants for each sex by age range and self-reported handedness, type of job, and according to thus practicing a musical instrument and sport.

Males (M), Females (F), right-handed (R), left-handed (L).

All participants gave their written informed consent before participating in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Department of Psychological Sciences Ethics Committee at Birkbeck (ref: 181996), University of London.

## *2.2. Data Collection Procedure*
