- As part of a longitudinal investigation of infants at familial risk for attention-deficit hyperactivity disorder (ADHD), mothers and fathers independently completed temperament ratings on their infants. In this paper, we examine the 7-, 12-, and 25-month temperament of 58 boys, 36 of whom were considered at familial risk for ADHD and 22 of whom were in the comparison group. Risk for ADHD was based on self-reported ADHD symptoms in the father. In addition, the influence of informant gender on temperament ratings was examined. The ADHD risk group received significantly higher scores for activity level and anger and lower scores for attentional shift, appropriate allocation of attention and inhibitory control. Their scores were also significantly lower on a composite measure of effortful control. Taken together, these findings offer support for the view of a link between early temperament and risk for ADHD. The only informant gender difference was for the activity level; mothers rated their sons as more active than did fathers. Copyright © 2008 John Wiley & Sons, Ltd.