**3.2 Sample characteristics**

Sample size was 85 people on average, with only two investigations engaging over a hundred participants. Only one study mentioned its sample source, which was individuals with autism and their relatives [16]. Two studies recruited participants from both sexes [16, 17], two recruited only males [18, 19], three selected only females [20–22], and one did not state the sexes of the participants [23]. Most of the participants were young adults [75%], while two studies included school-aged children (7–12 years) [16, 17]. No sample included infants, toddlers, preschoolers, adolescents, or elderly (**Table 1**).
