Symptoms of ADHD include inattentiveness, impulsiveness, and hyperactivity. The hyperactivity sometimes accompanied by inattentiveness, impulsiveness, and forgetfulness are cardinal symptoms associated with ADHD. ADHD is characterised by significant levels of hyperactivity, inattentiveness, and impulsiveness. Psychiatric disturbances such as irritability, impulsiveness, aggressiveness, and mood disturbances are also common. Children with DMDD often show several features of hyperactivity and impulsiveness characteristic of ADHD. It differs in having fewer or no typical symptoms of hyperactivity or impulsiveness. Excited catatonia is characterized by bizarre, non-goal-directed hyperactivity and impulsiveness. Eysenck originally suggested that extraversion was a combination of two major tendencies, impulsiveness and sociability. Studies have also indicated individual variation in temperament, such as sociability or impulsiveness. Hobbes is often the voice of reason, contrasting Calvin's manic impulsiveness. It summarizes key predictors of procrastination (expectancy, value, and impulsiveness) into a mathematical equation. He is often the voice of reason and prudence moderating Yoko's impulsiveness. Later Idaho-gholas tempered this with cynicism but the underlying impulsiveness remained. Three subscales are computed from this measure&colon; Impulsiveness, Venturesomeness, and Empathy. Turner notes that the episode illustrates Homer's impulsiveness, silliness, and "physical stupidity".