Temperament refers to early-appearing variation in emotional reactivity. The core dimensions of temperament and optimal method for assessment continue to be sources of considerable discussion. Nevertheless, the moderate stability of most temperamental traits and the strong influence of genetic and unique environmental factors have been well established, along with temperament's association with childhood psychiatric disorders. Both a temperamental predisposition toward experiencing negative emotions and low inhibitory control are linked to many psychiatric conditions, while other dimensions, such as levels of extraversion, vary by, and likely even within, disorders. Accumulating research directed at understanding the mechanism of these links between temperament and psychopathology indicate that, at least for most disorders, the two constructs cannot be viewed as simply different points along a shared continuum. The effect of temperament upon psychopathology has been found to be mediated and moderated by a number of both internal and external factors. Additional research is needed to help further define the core dimensions of temperament and the complex mechanisms through which temperamental traits interact with other influences in affecting developmental trajectories.
Keywordsanxiety; attention-deficit/hyperactivity disorder; children; personality; psychopathology; temperament The study of temperament and its relation to psychopathology has experienced a surge of interest and stands poised to alter our fundamental understanding of psychiatric disorders. Research in temperament and personality lay dormant for many years as psychodynamic and learning-based theories dominated the field. 1 When it rewoke, the literature of temperament (considered as part of normal human development) grew outside the purview of most clinical scientists. Since the landmark work of Thomas and Chess, 2 however, there has been a steady effort to bring these previously parallel lines of work together in mutually informative designs. This article will first briefly review some of the core concepts relating to temperament and its research, including the measurement of temperament and what is currently known about its origins and development. We will then turn to studies of the association between temperament and childhood psychiatric disorders, and also consider the possible mechanisms that may be involved. Finally, directions for future research will be addressed.