Personality is the dynamic and organized set of characteristics possessed by a person that uniquely influences his or her cognitions, motivations, and behaviors in various situations. It can also be thought of as a psychological construct complex abstraction that encompasses the person’s unique genetic background (except in the case of identical twins) and learning history and the ways in which these factors influence his or her responses to various environments or situations (Ryckman, 2013, p. 4) .
Psychologists employ the terms of Gordon Allport (1937) to define personality as the "dynamic organization within the individual of those psychophysical systems that determine his or her unique adjustment to the environment". And in the paragraph which follows, they specify that by dynamic organization they mean "an organized system (unitas multiplex) that is constantly evolving and changing", while the expression they borrow from Allport, 'within the individual', means that personality is what lies behind a specific individual’s acts. This definition is reflected in Marc D. Lewis' application of the principles of self organization to the development of dynamic cognitive-emotional systems. Lewis (Lewis, 2005: 173) writes: 'cognitive systems construed as dynamic systems do not process information transduced from the outside world; they reconfigure themselves in response to an ongoing stream of sensory events'. It is believed that personality is a complex system that evolves over time and which is a combination of two constitutive elements: temperament and character (Arciero & Bondolfi, 2009, p. 15).
Biological theorist Eysenck defined personality as a more or less stable and enduring organization of a person’s character, temperament, intellect, and physique, which determines his unique adjustment to the environment. Character denotes a person’s more or less stable and enduring system of cognative behavior (will); temperament, his more or less stable and enduring system of affective behavior (emotion); intellect, his more or less stable and enduring system of cognitive behavior (intelligence); physique, his more or less stable and enduring system of bodily configuration and neuroendocrine endowment. (Eysenck, 1970, p. 2) Thus, his definition emphasized traits (stable and enduring characteristics), which, when clustered together, are organized as types (Ryckman, 2013, p. 243).
Arciero, G., & Bondolfi, G. (2009). Selfhood, identity and personality styles. Hoboken, NJ: John Wiley & Sons.
Ryckman, R. M. (2013). Theories of personality (10th ed.). Belmont, CA: Wadsworth.