The subjects for the plasma cytokine level analysis (sample 1) [32] were recruited from male participants in two longitudinal studies of child development [15], [95] which identified four different trajectories of physical aggression from age 6 to 15 years: Males in the first trajectory showed very low or no physical aggression at any time-point (low-never); males in the second trajectory started with low-to-moderate rates of physical aggression but declined over time (moderate level desister); those in the third trajectory began with high rates of physical aggression but subsequently declined between ages 12 and 15 (high level desister); males on the fourth trajectory showed consistently high physical aggression from age 6 to 15 years (chronic physical aggression, CPA).
