Temperament and Borderline Personality Disorder

Temperament can be an important factor in the development of borderline personality disorder (BPD). The exact causes of BPD are not known; it is most often thought to be a combination of genetic (nature) and environmental (nurture) factors. Individual temperaments can predispose a person to develop BPD.

Temperament refers to our inborn personality traits, which are genetic in nature. The different ways infants interact with and react to their environment and experiences are reflective of their temperament, or behavioral style.

Efforts to understand individual differences in personality have occurred throughout history. Despite this, there is no clear consensus as to what the specific temperament traits are called or how they should be categorized. However, there have been some efforts to comprehensively describe temperament; one is the New York Longitudinal Study (NYLS).

In 1956, physicians Alexander Thomas and Stella Chess began The New York Longitudinal Study. Involving 185 children over six years, the authors identified nine distinct temperament traits present in every individual at birth. These traits as defined can be helpful in better understanding of how personality is impacted by genetic factors (or nature).

According to Thomas and Chess, these traits are areas of behavioral styles found in every individual. Each temperament listed should be seen as having a range or being a spectrum; some infants are going to be very distractible, others less distractible, and others even less. In the end, there are endless combinations of temperaments, making each infant unique at birth.

From The Origin of Personality:

• Adaptability
  • The ease with which a child adapts to changes in his environment
• Activity Level
  • The proportion of active periods to inactive ones
• Approach/Withdrawal
  • The response to a new object or person
• Distractibility
  • The degree to which extraneous stimuli affect behavior
• Intensity of Reaction
  • The energy of response regardless of its quality or direction
• Quality of Mood
  • The amount of friendly, pleasant, joyful behavior as contrasted with unpleasant, unfriendly behavior
• Persistence/Attention Span
  • The amount of time devoted to an activity and the effect of distraction on the activity
• Regularity/Rhythmicity
  • The regularity of hunger, excretion, sleep, and wakefulness
• Sensory Threshold
  • The intensity of stimuli required to evoke a discernible response

In general, temperaments exist as they are prior to birth and are a component of an individual’s personality. Although it is thought that temperaments are genetically determined, personalities as a whole are a combination of temperaments and experiences that shape and influence a person’s development.