Why Type D Personality Is Important, but Often Overlooked

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One of the most well-known concepts in psychology is the Type A Behavior Pattern, marked by extreme competitiveness, impatience, and the need for perfection. Although attaching the A to the syndrome was arbitrary at the time, the label has caught on, perhaps because it is so distinct and easy to remember. The term is aptly named, in addition, because the people who are high in this quality probably did consistently strive for A grades in school (or worse, an A-plus). Following the identification of Type A in the early stress literature, a Type B was soon to follow as the opposite of Type A. Type C personality became identified next as the “conscientious” individual, concerned with accuracy and quality over the Type A’s insistence on getting things done quickly.

The alphabetical list of personality types ends with the fourth category, named Type D for distressed. Individuals in this group are likely to be anxious, lonely, and perhaps even traumatized, all of which cause their mental health to suffer. These individuals may also be vulnerable to cardiovascular disease, but for different reasons than the highly stressed and time-pressured Type A. People high in the Type D qualities of anxiety and depression have a poor prognosis when they develop ischemic heart disease, in which blood supply is cut off to the heart, producing chest pain (angina). Paradoxically enough, Type D individuals may not actually experience anxiety and depression in terms of mood state (how they feel), because they suppress their negative emotions. By trying to reign in their negative feelings, they only exacerbate their risk of cardiac disease.

As noted by University of Northern Colorado’s Michael Allen and associates (2018), the Type D personality can be thought of as involving high levels of negative affectivity (NA) combined with high levels of social inhibition (SI). Allen et al. believe that people high in the Type D personality traits are likely to show more generally high levels of behavioral inhibition (BI), defined as a tendency to avoid or withdraw from novel situations. BI predisposes an individual to develop anxiety-related disorders if exposed to certain environmental stressors. Military personnel high in BI, for example, are more likely to develop post-traumatic stress disorder (PTSD) than their counterparts who do not have this temperament.

Allen and his co-authors propose that BI operates to predispose individuals to psychological distress through a “learning diathesis” model, which creates a stronger reaction to stimuli that signal an aversive event. Classic eye-blink conditioning provides an experimental model for this process. A particular sound won’t cause an eye to blink on its own, but if that sound is paired with an aversive stimulus, such as a puff of air, your eyelid will blink to that sound alone once learning has been established. The cause of this learned response, the University of Northern Colorado team propose, is the activation of a part of the brain known as the amygdala, along with another nearby brain region, the hippocampus, which is involved in the consolidation of memory.

The focus of the Allen et al. study was on expanding the notion of diathesis learning to the Type D personality with its added component of negative affectivity, which, in turn, may be related to reductions in the hippocampus. Although BI should heighten the activation of the amygdala, and hence increase the rate of eye-blink conditioning, the effect of the Type D personality would be to reduce the eye-blink conditioning learning curve thanks to a reduced hippocampal volume (poorer memory).

The research team exposed their sample of 89 college students (63 females) to an eye-blink conditioning procedure in which their eye-blink responses served as the outcome variable. They also completed measures of BI (Gladstone & Parker, 2005) and Type D personality (Denollet, 2005). Questions on the BI scale included: “Do you tend to observe strangers from a distance first, before being able to mix in?”; “Do you tend to introduce yourself to new people?" (reverse scored); and “Do you prefer your own company to the company of others?”

The 14 items on the Type D personality measure that rates negative affectivity included: “I am often in a bad mood”; “I often find myself worrying about something”; and “I often make a fuss about unimportant things.” The social inhibition questions on the Type D scale are similar to those measuring BI, such as “I find it hard to start a conversation.”

As the authors predicted, individuals high in both the BI and SI components of the Type D personality measure showed more rapid eye-blink conditioning, supporting the idea that the socially inhibited person is highly vigilant to stimuli in the environment. The findings for negative affectivity were less clear-cut, as there was no difference in conditioning rates for individuals classified as high vs. low on this component of the Type D measure. Cautioning that further research is needed, the authors noted, “It appears that NA acts like a hippocampal lesion (p. 99),” which would support the idea that depression has a neural basis.

From this study’s findings, it appears that Type D personality, particularly the inhibited component, does seem to have a role to play in an individual’s overall mental health, above and beyond its relationship to cardiac disease. The heightened vigilance that represents social inhibition, tested in this study via a conditioning paradigm, means that, as the authors conclude, there is “an increased risk of developing anxiety disorders in anxiety-prone individuals when exposed to aversive stimuli” (p. 101).

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To sum up, you can see that the Type D personality is a measurable entity that shows up in a specific pattern of responses to a classical conditioning paradigm. The fact that this is a “real” personality construct suggests that it is worth paying attention to if you, or someone you care about, has these tendencies. Mental and physical health are intimately linked, and finding fulfillment in life means trying to maximize both.