As noted by the well-known historian of .E. Berrios (1993), the behaviors described by current (PD) categories have been identified and described throughout the course of history. (See Bornstein, [2006], Coolidge & Segal [1998], and Millon [1981] for similar discussions.) Accordingly, there have always been withdrawn, detached, and isolated individuals, but the theories and terminology used to explain them have changed over time.

Antiquity

In the early history of classification, temperament and character were distinct entities, with temperament closely associated with the medical model, and character associated with and literature (Millon 1981; Roback, 1928). Aristotle (trans. 1897, trans. 1912), Theophrastus (trans. 2004), Epictetus (trans. 1877), and later La Bruyere (as cited in Roback, 1928), among others, identified and described isolated, detached, and withdrawn individuals in literature and philosophy, or what has been called “literary characterology” (see Lombardo & Foschi, 2002; Millon, 1981; Roback, 1928; for overviews of this perspective).

Literature and Philosophy

This genre provided brief narrative/story-like vignettes intended to highlight the prototypical features of various character types (Millon, 1981; Roback, 1928). For instance, Theophrastus (trans. 2004, p. 109) identified withdrawn, detached, and isolated individuals as self-centered in his well-known book, Characters. Theophrastus emphasized their dismissing attitude as well as an unwillingness to socialize or engage in recreational activity.

Aristotle (trans. 1897, trans. 1912) described isolated individuals as unnatural, animal-like, and incapable of experiencing joy, perhaps foreshadowing some later conceptualizations of individuals as pathological, primitive, and anhedonic (e.g., see McWilliams, 2004, for a related discussion and counterview). In addition, Aristotle (trans. 1912) conceptualized human nature as consisting of both a sociable and a reclusive side, with the solitary side linked with unhappiness and immorality.

Epictetus (trans. 1877) provided a description of solitary individuals that went beyond surface behaviors and -based judgments common to literary characterology (see Roback [1928] and Millon [1981] for similar discussions). For instance, Epictetus (trans. 1877) differentiated solitariness as a subjective experience connected with from the adaptive capacity to be solitary, which is similar to Winnicott’s (1958) later view of the capacity to be alone. In Epictetus’s (trans. 1877) work, there is a conceptualization of solitariness which highlights the various ways in which ostensibly socially isolated individuals may experience being alone, something that forecasts contemporary psychoanalytic approaches which emphasize the description of the subjective experience of isolated, detached, and withdrawn individuals (e.g., Martens, 2010; McWilliams, 1994, 2004; see Roback, 1928, for a discussion of the connection between literary characterology and psychoanalytic literature).

In sum, both Aristotle (trans. 1897, trans. 1912) and Epictetus (trans. 1877) emphasized the multidimensional nature in what has proven to be one of the most basic and enduring traits in personality psychology, namely the tendency toward being social versus asocial or what was later called the - dimension by Hans Eysenck (for overviews, see Maher & Maher, 1994; Winter et al., 1998; see also Merenda, 1987).

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Medical Model

In contrast to discussions of character in early Greek literature and philosophy, the medical model, derived from the work of Hippocrates (ca 460 BCE), emphasized the biological basis and categorical classification of disease (see Millon, 1981; Roback, 1928; and Stelmack & Stalikas, 1991, for reviews).

Hippocrates’ well-known theory of four “humors” (i.e., phlegm, yellow bile, black bile, and blood) was the primary theory of medicine during the Greco-Roman period (see Berrios, 1993; Coolidge & Segal, 1998; Maher & Maher, 1994; Millon, Millon, Grossman, Meag, & Ramnath, 2004; Tyrer, Coombs, Ibrahimi, Mathilakath, Bajaj, Ranger, Rao, & Din, 2007; and Veith, 1957, for overviews of the early /Hippocratic-model). In this theory, the humors were considered to be physical/somatic-based constructs—substances or fluids—that purportedly existed at different levels of strength in different individuals. Tyrer et al. (2007) reported that following Hippocrates’s work, Galen—during the 2nd century ACE—identified four separate personality styles or temperaments associated with heightened levels of each of the four humors (see Lester, 1990; Merenda, 1987; and Millon, 1981, for similar discussions; see also Coolidge & Segal, 1998; Maher & Maher, 1990; Veith, 1957; and Millon et al., 2004).

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Extant literature has credited the “Hippocratic-Galen theory” for describing the “phlegmatic temperament” as characterized by indifference and apathy, traits now conceptualized as -IV schizoid PD characteristics (see Stelmack & Stalikas, 1991; Lester, 1990; Merenda, 1987; Millon, 1981; Millon et al., 2004; Tyrer et al., 2007; cf. DSM-IV APA, 1990). For example, according to recent work by Tyrer et al. (2007), the phlegmatic temperament was re-labeled as schizoid, inhibition, introverted, asocial, and cluster A by various recent researchers, all referring to essentially the same phenomena (i.e., withdrawn, detached, and isolated individuals).

Contrary to this popular view, Stelmack and Stalikas (1991) showed that Hippocrates’s theory of humors did not make any reference to personality, and Galen’s temperament types only referred to personality factors tangentially without any reference to a phlegmatic (schizoid) personality construct. However, the language used to label the humors was linked with certain physical properties (e.g., phlegm was linked with coldness, Stelmack & Stalikas, 1991; for overviews, see also Coolidge & Segal, 1998; Veith, 1957) that connote personality characteristics associated with schizoid PD (cf. DSM-IV, APA, 1990).