Introverts Aging, Gracefully

The recent ScienceDaily.com article (June 18, 2009; 1) entitled “Life Force Linked to Body’s Ability to Withstand Stress” caught my attention. Always interested in ways to live a longer, healthier, lower-stress life,  I thought this research might provide a path to nonagenarian status.

The second sentence began “Especially in aging women …” . Right, I aspire to someday make “aging woman” status. It continued “ …low levels of the personality trait extraversion may signal that blood levels of a key inflammatory molecule have crossed over a threshold linked to a doubling of risk of death within five years.” In simpler terms, the results showed that persons with low extroverted tendencies (introverts) had higher levels of a marker for inflammation, and thus a greater risk of death.

Hold the phone! Could my dream of living beyond my grandparents’ lifespan (or at least to make my final house payment) be dashed simply because I’m an introvert?

I ‘m of relatively good health: Cholesterol and blood glucose levels are within a normal range and I exercise regularly (dog walks count, right?). My blood pressure is within a healthy range, that is until I read that persons with my introverted tendencies are headed to an early grave.  Now another personality trait, skepticism, takes over. Let’s examine further.

The study, published in the journal Brain, Behavior and Immunity, is the work of Benjamin Chapman, Ph.D., assistant professor in the Rochester Center for Mind-Body Research, at the University of Rochester Medical Center. In his research Chapman found that extroverts, particularly those with ‘high dispositional activity’ have significantly lower levels of the inflammatory cytokine interleukin-6 (IL-6) than their introverted counterparts (2).  For the purpose of this study, lower IL-6 means lower risk of death.

Psychiatrist Carl Jung described extroverts as focused on the external world, and most happy when active and surrounded by people. Introverts were said to ‘look inward’ and were described by Jung as shy. The definition of extraversion was refined in the 1930s when psychologist Gordon Allport and others settled on five general trait clusters: extraversion vs. introversion, emotional stability vs. neuroticism, openness vs. closed-minded, agreeable vs. hostile and conscientiousness vs. unreliability. These traits became known as the Five Factor model of personality.  In the 1990s extroversion was additionally described as: 1) a tendency toward happy thoughts; 2) a desire to be around others; and 3) an innate sense of vigor or active engagement (dispositional energy).  The Chapman  study used  the Five Factor model , plus the effects  of high and low dispositional energy, to describe the subjects in their work.

Does anyone detect a decidedly good vs. bad theme here, with extroversion holding all the good cards? Are introverts once again getting a bad rap? As Jonathan Rauch pointed out in “Caring for Your Introvert” (The Atlantic, 2003) the classic introvert/extrovert definitions leave something to be desired (3).

Chapman’s study took ‘the important first step of finding a strong association between one part of extroversion and a specific stress-related, inflammatory chemical’. The authors figured that if low dispositional activity could be linked to inflammation, they could design treatments to ‘help high-risk patients become more engaged in life as a defense against disease.’

Chapman noted that they couldn’t conclude absolutely that low dispositional activity caused inflammation or whether inflammation was taking a toll on people by reducing personality tendencies. This may be an important detail to delineate before prescribing something like a daily jig in a crowded room to improve an introvert’s life expectancy.

Because one good experiment frequently provokes another, this introvert proposes a follow-up study: Would exposure to fewer people with ‘high dispositional activity’ lower an introvert’s levels of the inflammatory cytokine IL-6, thus extending her/his life expectancy?

Since many of you are Scientists,  a few statistics about introversion (I) and extroversion (E) and their distribution amongst general science categories (4):

• Biological sciences: I=52.6, E=47.3
• Physical sciences: I=55.3, E=44.6
• Chemistry: I=62.3, E=37.7

 

References

1. University of Rochester Medical Center (2009, June 18).’Life force’ linked to body’s ability to withstrand stress. ScienceDaily. Retrieved July 24, 2009 from www.sciencedaily.com/releases/2009/06/0906171237000.htm
2.  Chapman, B. et al. (2009) Gender, race/ethnicity, personality, and interleukin-6 in urban primary care patients. Brain, Behavior and Immunity 23, 636-42. PMID: 19162168
3. http://www.theatlantic.com/doc/200303/rauch  (March, 2003). Caring for Your Introvert. Retrieved 27-July-09.
4. Briggs Myers, I. and McCaulley, M. (1985) Manual: A guide to the development and use of the Myers Briggs Type Indicator. Consulting Psychologists Press, Inc.