In 1987, Cloninger proposed a bio-social model of personality based on four temperamental dimensions exhibited early in life and related to specific neurotransmission systems, such as dopamine, serotonin and norepinephrine. The temperamental dimensions include: search of novelty (NS), harm avoidance (HA), reward dependence (RD) and persistence (P). Three other character dimensions, founded on an information synthesis of social, cognitive and personality development according to humanistic and transpersonal model, completet this dimensions. Cloninger model is set up as a complex dynamic system in which the biological elements are combined with family, social, and cultural influences. According to Cloninger, temperament refers to ‘the patterns of individual automatic lifelong emotional response’ , while character refers to the ‘ self-concept and individual differences in objectives and values, influencing voluntary election, the intentions and the sense of what is experienced in life.’ This book discusses individual differences, social and environmental influences and impact on quality of life of temperaments. Chapter one provides a summary of the extensive research on eating disorders (EDs) patients’ personality. Chapter two and three assess the relationships between temperament dimensions and psychopathology in eating disorders using the TCI. Chapter four examines relevant research studies on the change of emotion regulation and its connections and influence on social relationship and academic success in young childre. Chapter five studies and develops tests for assessing temperament and affective states by behavioural criteria and to assess welfare during machine milking and lambing of dairy sheep on farm conditions. The last chapter reviews convergence between several distant disciplines: neurochemistry, kinesiology, clinical psychophysiology and differential psychology.