The complex genetics and biology of human temperament: a review of traditional concepts in relation to new molecular findings

Abstract

Recent genome-wide association studies (GWAS) have shown that temperament is strongly influenced by more than 700 genes that modulate associative conditioning by molecular processes for synaptic plasticity and long-term learning and memory. The results were replicated in three independent samples despite variable cultures and environments. The identified genes were enriched in pathways activated by behavioral conditioning in animals, including the two major molecular pathways for response to extracellular stimuli, the Ras-MEK-ERK and the PI3K-AKT-mTOR cascades. These pathways are activated by a wide variety of physiological and psychosocial stimuli that vary in positive and negative valence and in consequences for health and survival. Changes in these pathways are orchestrated to maintain cellular homeostasis despite changing conditions by modulating temperament and its circadian and seasonal rhythms. In this review we first consider traditional concepts of temperament in relation to the new genetic findings by examining the partial overlap of alternative measures of temperament. Then we propose a definition of temperament as the disposition of a person to learn how to behave, react emotionally, and form attachments automatically by associative conditioning. This definition provides necessary and sufficient criteria to distinguish temperament from other aspects of personality that become integrated with it across the life span. We describe the effects of specific stimuli on the molecular processes underlying temperament from functional, developmental, and evolutionary perspectives. Our new knowledge can improve communication among investigators, increase the power and efficacy of clinical trials, and improve the effectiveness of treatment of personality and its disorders.

Three genetic–environmental networks for human personality

“…Specifically, we found three clusters of people who were distinguished by heritable configurations of the temperament traits related to individual differences in procedural learning of habits and skills [19]. The three clusters were also characterized by individual differences in automatic behavioral activity and emotional expression, and corresponded closely to temperament clusters described as "easy", "difficult", and "slow to warm-up" [8,11,29] (Supplementary Information, see Tables S1, S2, and reference [8] for review). People in our "reliable" cluster resembled children with an "easy temperament" and adults who were conscientious extraverts because they were well controlled in activity and were warm and calm emotionally; put another way, they were high in Reward Dependence (i.e., sentimental, friendly, and approval seeking), low in Novelty Seeking (i.e., deliberate, thrifty, and orderly), low in Harm Avoidance (i.e., optimistic, confident, outgoing, and vigorous), and high in Persistence (i.e., determined).…”

“…Different genetic and neurobiological systems are involved in regulating distinct aspects of personality, which are traditionally described as temperament and character [5][6][7][8]. Temperament refers to innate biological predispositions that influence automatic emotional reactivity and habits; it is moderately stable throughout the lifespan, but can develop with aging and behavioral conditioning [1,9,10].…”

Personality Traits as Markers of Psychosis Risk in Kenya: Assessment of Temperament and Character

“…Detailed reviews of the TCI, including an analysis of its reliability and validity, are available elsewhere. 9 , 46 …”

The Yin-Yang personality from biopsychological perspective using revised Sasang Personality Questionnaire

“… 17 , 30 , 37 , 38 , 39 When we put these associations together, the Yin-Yang (Eum-Yang) theory corresponds well to Western notions of temperament 2 , 19 , 20 and the balance and health 21 , 40 of personality depends on integrative learning processes designated as character in the West. 41 , 42 , 43 …”