Modern psychobiologic research conceptualizes personality as a complex adaptive system involving a bidirectional interaction between heritable neurobiologic dispositions (temperament) and social learning (character). In this study we evaluated temperament and character traits of patients with anorexia nervosa and their mothers and fathers and we analyzed the correlation of temperament and character traits among family members in anorectic families. Finally we tested the ability of the Temperament and Character Inventory (TCI) to discriminate between normal controls and anorectic subjects their parents and their families. Temperament and character features of 50 restricter anorectic patients and their parents (23 fathers and 25 mothers) were analyzed and then compared with a control group of 60 women and their 20 fathers and 20 mothers using the TCI. Data suggest that both temperament and character factors are involved in anorexia nervosa (AN). Anorectic individuals were high in harm avoidance (HA) low in novelty seeking (NS) and high in persistence (P) ("obsessive temperament type"). Their character was remarkable for low self-directedness (SD). Their mothers were distinguished by low SD. The fathers were high in HA but also low in P and high in reward dependence (RD). Again they were low in SD. The anorectic family had low SD as a common denominator observed in all family members. This finding indicates that the psychopathology of AN extends beyond obsessiveness but combines obsessiveness with low character development. None of the above temperament and character profiles is pathognomic of restricter anorectics. The observation that both temperament and character have an important role in the etiopathogenesis of AN has important treatment ramifications. The TCI was useful in discriminating between normal controls and anorectic subjects their parents and the whole anorectic family.