"... Joel Nigg has found that excessively irritable infants are more likely to become children who cannot regulate their anger or impulses when frustrated, while excessively exuberant infants are more likely to become impulsive children. In both cases, the development of effortful control is inhibited. These findings have led Nigg to propose that ADHD is not a disorder of inattention or hyperactivity, but instead a disorder of temperament-based self-regulation"
"... Joel Nigg has found that excessively irritable infants are more likely to become children who cannot regulate their anger or impulses when frustrated, while excessively exuberant infants are more likely to become impulsive children. In both cases, the development of effortful control is inhibited. These findings have led Nigg to propose that ADHD is not a disorder of inattention or hyperactivity, but instead a disorder of temperament-based self-regulation"