Objective: To examine whether males and females with ADHD differ in their preferences for delayed rewards, since there is some evidence that suggests a sex difference with typically developing (TD) samples. Method: We used meta-analyses to examine sex differences on delay of gratification and temporal discounting tasks in both TD and ADHD samples. We identified 28 papers with 52 effect sizes for children and adults, and calculated the average effect size for sex comparisons within TD and ADHD samples. Results: The estimated mean difference between TD males and TD females was negligible, but males with ADHD were more likely to choose the larger delayed rewards than females with ADHD. Meta-regressions indicated that task type, age, and reward type did not significantly predict sex differences. Conclusion: These findings suggest that females referred for ADHD may make less adaptive choices by preferring smaller immediate rewards over larger delayed rewards more often than males with ADHD. Implications of our findings are discussed.

Estimations of competence paradigms offer methods to help us measure how well we track our performance. Bridging across the clinical research and metacognitive research traditions, we identified the Positive Illusory Bias (PIB), metamemory and meta-reasoning paradigms for assessing estimation of competence in neurodevelopmental conditions. Overall, studies from PIB paradigms suggest that individuals with Attention-Deficit Hyperactivity Disorder, Autism, Intellectual Disability and Learning Disability tend to display a positive bias in their performance relative to other informants. In metamemory paradigms, individuals with these neurodevelopmental conditions tend to show more discrepancy between their subjective judgments and their memory performance relative to comparison controls, but these findings have been less consistent than for PIB. Meta-reasoning has been less well-studied across neurodevelopmental conditions. In order to advance our understanding of whether estimation of competence is a significant domain for understanding neurodevelopmental conditions, consideration must be given to conceptual models for each neurodevelopmental condition, methodological issues (paradigm selection and interpretation of self-report and subjective judgment) and developmental considerations.