Currently, diagnostic criteria for ADHD mainly reflect behavioral symptoms, neglecting internal phenomena like mind-wandering. Recent studies found that mind-wandering explains impairment beyond ADHD ...symptoms in adults. To better capture ADHD-related impairment in adolescents, we aimed to elucidate whether mind-wandering is associated with impairments that are prevalent in adolescents (i.e., risk-taking behavior, homework problems, emotional dysregulation, and general impairment) beyond ADHD symptoms. Furthermore, we sought to validate the Dutch translation of the Mind Excessively Wandering Scale (MEWS). We assessed a community sample of 626 adolescents on ADHD symptoms, mind-wandering, and the impairment domains. The Dutch MEWS had good psychometric properties. Mind-wandering was linked to general impairment and emotional dysregulation beyond ADHD symptoms, but was not linked to risk-taking behavior and homework problems beyond ADHD symptoms. Internal psychological phenomena such as mind-wandering may add to the behavioral symptoms of ADHD in explaining part of the impairment that adolescents with ADHD characteristics experience.
Many people have flipped coins but few have stopped to ponder the statistical and physical intricacies of the process. In a preregistered study we collected \(350{,}757\) coin flips to test the ...counterintuitive prediction from a physics model of human coin tossing developed by Diaconis, Holmes, and Montgomery (DHM; 2007). The model asserts that when people flip an ordinary coin, it tends to land on the same side it started -- DHM estimated the probability of a same-side outcome to be about 51%. Our data lend strong support to this precise prediction: the coins landed on the same side more often than not, \(\text{Pr}(\text{same side}) = 0.508\), 95% credible interval (CI) \(0.506\), \(0.509\), \(\text{BF}_{\text{same-side bias}} = 2359\). Furthermore, the data revealed considerable between-people variation in the degree of this same-side bias. Our data also confirmed the generic prediction that when people flip an ordinary coin -- with the initial side-up randomly determined -- it is equally likely to land heads or tails: \(\text{Pr}(\text{heads}) = 0.500\), 95% CI \(0.498\), \(0.502\), \(\text{BF}_{\text{heads-tails bias}} = 0.182\). Furthermore, this lack of heads-tails bias does not appear to vary across coins. Additional exploratory analyses revealed that the within-people same-side bias decreased as more coins were flipped, an effect that is consistent with the possibility that practice makes people flip coins in a less wobbly fashion. Our data therefore provide strong evidence that when some (but not all) people flip a fair coin, it tends to land on the same side it started. Our data provide compelling statistical support for the DHM physics model of coin tossing.
