Social Behavior & Personality

A loved one’s personality and social interaction often change as a result of neurodegenerative disease. Sometimes these changes are small and do not significantly change our sense of who the person is. Other times, drastic changes in personality can occur, and these can be difficult for caregivers to cope with and to accept. Until recently, cognitive and behavior changes have been the focus of dementia researchers, and the scientific community has only just begun to characterize the kinds of social changes these diseases can cause.

Personality
Personality research has shown that there are five major aspects of personality:

• extraversion
• openness
• agreeableness
• conscientiousness
• neuroticism

Everyone’s personality can be measured according to the degree to which they express, or do not express, these traits:

Extraversion
Extraverted personalities tend to be characterized by sociability, assertiveness, talkativeness, and activity. Extraverted people tend to prefer large groups to small gatherings. Introverted personalities tend to be independent, reserved and even-paced. They typically value solitude and experience less exuberant emotions. Facets of the extraverted personality include warmth, gregariousness, assertiveness, activity, excitement-seeking, and positive emotions.

Decreased extraversion is a common, early symptom that can be caused by almost every neurodegenerative disease. Some patients show only mild social withdrawal (such as in Alzheimer’s disease), while others may become extremely introverted (a common result of frontotemporal dementia).

Openness
Open personalities tend to have an active imagination, aesthetic sensitivity, attentiveness to inner feelings, intellectual curiosity, preference for variety and independent judgment. They are willing to entertain novel ideas and unconventional values. They experience positive and negative emotions more keenly than closed individuals. Elements of this personality include fantasy, aesthetic appreciation, emotional receptivity, novelty seeking, intellectual curiosity, and willingness to re-examine values.

It is common for individuals with a neurodegenerative disease to become less open to novelty, partly because this sort of behavior requires significant cognitive resources that dementia patients no longer have. It is simply easier to stick to familiar ways when their lives become a daily challenge. However, some patients with neurodegenerative disease develop a type of pathological mental rigidity that is a direct result of damage to parts of the frontal and temporal lobes.

Agreeableness
Agreeable personalities tend to be sympathetic toward others, altruistic in behavior and believe that others will be equally helpful in return. In contrast, antagonistic individuals tend toward egocentrism, skepticism of other’s intentions and competitive rather than cooperative behaviors. Components of the agreeable personality include trust, straightforwardness, altruism, compliance, modesty, and tender-mindedness.

Many individuals with neurodegenerative disease, including Alzheimer’s disease patients, may NOT show any significant changes in agreeableness. This trait is commonly preserved until late in the disease process. However, diseases like semantic dementia have been shown to cause significant decreases in agreeableness early in the disease, particularly when the right temporal lobes are damaged.

Conscientiousness
Conscientious personalities are characterized by a will to achieve. They tend to be purposeful, determined and steadfast. In its most positive manifestation, people with this personality trait are high achievers; on the negative side, this characteristic can lead to irritating perfectionism, compulsive demands and workaholic behaviors. This personality is characterized by competence, order, dutifulness, achievement striving, self-discipline, and deliberation.

It is typical of almost all individuals with neurodegenerative disease to show decreased conscientiousness. The mental energy, attention to detail, and exacting memory that is required to maintain a high level of conscientiousness is too difficult for a dementia patient to consistently maintain.

Neuroticism
Neurotic personalities tend to be vulnerable to psychological stress. Negative emotions such as embarrassment, insecurity, sadness, anger, fear and guilt are more likely to be experienced. Cluster traits that define this personality are anxiety, angry hostility, depression, self-consciousness, impulsiveness and vulnerability.

Neurodegenerative disease makes individuals much more vulnerable to stress, both because it is easier to become overwhelmed by the challenges posed by the disease and because these diseases often directly affect the brain’s neurotransmitters, reducing one’s psychological resilience. Increased neuroticism is common for many individuals with a neurodegenerative disease, though not all, and tends to worsen as the disease progresses.

Social Interaction
Changes in a loved one’s social interaction often accompany personality changes. These changes may occur because of structural and neurochemical changes in the brain that affect a person’s ability to process and act on information. Common functional areas affected by dementia are:

Self-awareness — Being able to reflect on one’s actions, how these actions may be interpreted by others, and the ability to modify one’s behavior accordingly.

Other-awareness — Being able to both recognize and interpret another’s emotions and intentions and to respond to them appropriately.

Adherence to Social Norms — An understanding and adherence to social norms and situation-appropriate behavior, an avoidance of punishment, ostracism, ridicule or making others uncomfortable.

Interpretation of Social Behavior — the ability to understand situations, to follow conversations, to distinguish between what is said and what is implied.

Interpretation of Emotional Cues — the ability to understand facial expressions, emotions in a person’s voice, body posture and gesticulations.

The neuroanatomy of personality is not well understood. Structures throughout the brain are thought to be involved, including the frontal lobes and the right temporal lobe. Alterations in neurochemistry may also be responsible for changes in personality and social interaction. Though until recently, very little direct study of social interactions in individuals with neurodegenerative disease has been performed, and this is a special area of interest for the MAC. A number of research projects are currently underway at the MAC that will provide greater insight into changes in these areas.

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