Schizoids are impressive not for what they do, but for what they fail to do. The schizoid is probably best described as the reverse of the histrionic personality (HPD). Whereas histrionics are turned radically outward toward the social world, schizoids are radically detached. Whereas histrionics are hyperemotional, schizoids lack the capacity for deep emotional experience. Whereas histrionics are demonstrative, dramatic, spontaneous, and theatrical, schizoids are unanimated, robotic, and lacking in energy and vitality. Whereas histrionics demand the center of attention, schizoids are socially disinterested. Whereas histrionics are hyper-sexualized, schizoids have little or no interest in such matters. Whereas histrionics are cognitively scattered and unable to focus, schizoids either focus intensely and creatively or, in their more severe form, become so withdrawn that they lack any motivation for sustained concentration. Whereas histrionics employ massive repression as their principal defense mechanism, schizoids either intellectualize or have so few conflicts and drives that there is little to repress.
They are notably unlike the painfully shy avoidant personality (AvPD), who desperately desires intimacy and acceptance but fears shame, humiliation, and embarrassment. Rather, the schizoid is avoidant of intimacy out of pure indifference. Because schizoids are socially detached, they are often perceived as insensitive, cold, and humorless. Schizoids are indeed insensitive but in the same way that a scale might not display your weight correctly. They are not harsh or callous by nature. Normal persons manage their interpersonal presentation automatically at a level below conscious awareness. Social perception and reaction are so routine that social encounters run smoothly. Such abilities normally begin to develop at birth, with the attachment between mother and infant, and continue to grow in sophistication over most of the life span.
In contrast, schizoids lack internal models by which to represent interpersonal behavior. They may fail to reciprocate even smiles or nods, for example. Their appraisals about the intent, goals, and feelings of others are likely to be wrong much of the time or informed by factors that most of us would consider tangential or irrelevant, especially where communications have some subtle aspect or convey information related to feelings of conflict or irony. Whereas every normal person understands what it is like to be pulled in two different directions at once, the famous approach-approach conflict, such communications are far too complex for most schizoids. In more severe cases, the scope of understanding may not extend to even the coarsest categories of emotional experience�those basic emotions that primate theorists view as being hardwired into human nature, such as joy, surprise, disgust, anger, and fear. For this reason, schizoid are referred to as an interpersonal �black hole,' with signals disappearing forever without leaving a trace.