Dev Psychopathol. 2021 Dec;33(5):1837-1848. doi: 10.1017/s0954579421001012. Epub 2021 Oct 15. ABSTRACT High levels of early emotionality (of either negative or positive valence) are hypothesized to be important precursors to early psychopathology, with attention-deficit/hyperactivity disorder (ADHD) a prime early target. The positive and negative affect domains are prime examples of Research…