Anxiety:  Inherited Through Genetics?

Robin Marantz Henig is an author who has reviewed a longitudinal study completed at Harvard University, which seeks information regarding people who tend to be anxiety prone or have an anxious disposition.

Kagan’s study began in 1989 when he was a professor of psychology at Harvard and was working on a major longitudinal study of temperament and its effects.  Kagan describes temperament as a complex, multilayered thing.  Kagan was studying one single dimension: whether babies were easily upset when exposed to new things. This characteristic was singled out as worthy of studying both because it could be measured and because it seemed to explain much of normal human variation. Kagan took information and results from a study he had just completed on toddlers, that the most edgy infants were more likely to grow up to be inhibited, shy and anxious. Kegan viewed and studied videotapes of the first babies in the study, looking for the irritable behavior he would later call high-reactive.

While viewing the videos, Kagan determined that there were no high-reactors among the first 18. They gazed calmly at things that were unfamiliar. But the 19th baby was different. She was distressed by novelty — new sounds, new voices, new toys, new smells.  He concluded this by the baby’s response of flailing her legs, arching her back and crying. Here was what Kagan was looking for but was not sure he would find: a baby who essentially fell apart when exposed to anything new.

Kagan followed the development of this baby. He found that baby 19 grew up true to her temperament.  The longitudinal study continued with all babies.  Baby 19 is a plain-looking teenager, hiding behind her long, dark hair. The interview, the same one given to all 15-year-olds in the longitudinal study, begins with questions about school. She has very few extracurricular activities, she says in a small voice, but she does like writing and playing the violin. She fidgets almost constantly as she speaks, twirling her hair, touching her ear, jiggling her knee. “This is the overflow of her high-reactive nature,” Kagan stated.

In the interview, the interviewer asks Baby 19 what she worries about.

“I don’t know,” Baby 19 says after a long pause, twirling her hair faster, touching her face, her knee. She smiles a little, shrugs. Another pause. And then the list of troubles spills out: “When I don’t quite know what to do and it’s really frustrating and I feel really uncomfortable, especially if other people around me know what they’re doing. I’m always thinking, Should I go here? Should I go there? Am I in someone’s way? ... I worry about things like getting projects done... I think, Will I get it done? How am I going to do it? ... If I’m going to be in a big crowd, it makes me nervous about what I’m going to do and say and what other people are going to do and say.” Baby 19 is wringing her hands now. “How I’m going to deal with the world when I’m grown. Or if I’m going to sort of do anything that really means anything.”   Her voice trails off.  She wants to make a difference, she says, and worries about whether she will. “I can’t stop thinking about that.”

Baby 19, now grown up, has been able to voice all the things that really upset her and make her anxious.  At this point, she is highly anxious about most things.  Some people, no matter how robust their stock portfolios or how healthy their children, are always mentally preparing for doom. Kagan felt this was true of baby 19. They are just born worriers, their brains forever anticipating the dropping of some dreaded other shoe. For the past 20 years, Kagan and his colleagues have been following hundreds of such people, beginning in infancy, to see what happens to those who start out primed to fret. Now that these infants are young adults, the studies are yielding new information about the anxious brain.

Psychologists have often thought that innate temperament is a reality. Or stated differently, we can be predisposed to be anxious. Four significant long-term longitudinal studies are now under way: two at Harvard that Kagan initiated, two more at the University of Maryland under the direction of Nathan Fox, a former graduate student of Kagan’s. With slight variations, they all have reached similar conclusions: that babies differ according to inborn temperament; that 15 to 20 percent of them will react strongly to novel people or situations; and that strongly reactive babies are more likely to grow up to be anxious.  A huge finding is that Kagan has concluded is that while temperament persists, the behavior associated with it doesn’t always. 

Kagan has identified three ways to identify an emotion: the physiological brain state, the way an individual describes the feeling and the behavior the feeling leads to. Accoding to Kagan, “Not every brain state sparks the same subjective experience; one person might describe a hyperaroused brain in a negative way, as feeling anxious or tense, while another might enjoy the sensation and instead uses a positive word like “alert.” Nor does every brain state spark the same behavior: some might repress the bad feelings and act normally; others might withdraw.”  Kagan believes that, “While the behavior and the subjective experience associated with an emotion like anxiety might be in a person’s conscious control, physiology usually is not. He calls this “the long shadow of temperament.” The oldest high-reactive subjects in Kagan’s and Fox’s studies, like Baby 19, are in their 20s now.  And they remain anxious, hypervigilant and difficulty with focus and restlessness til this time. 

Anxiety is fear gone awry.  Anxiety is very much involved in our heads which then produces a physiological response.  The brain produces thoughts that can produce over-reactivity in the amygdale.  Kagan found that in high-reactive study subjects, the amygdala is hyperreactive, prickly as a haywire motion-detector light that turns on when nothing’s moving but the rain. Other physiological changes exist in children with this temperament, many of them also related to hyperreactivity in the amygdala. They have a tendency to more activity in the right hemisphere, the half of the brain associated with negative mood and anxiety; greater increases in heart rate and pupil dilation in response to stress; and on occasion higher levels of the stress hormones cortisol and norepinephrine.

To summarize, Baby 19, she has not yet gone against her personality type, and odds are she never will.  According to Kagen, she is doing well in college, "but her temperament still comes through in her personality. Kagan said Baby 19 tends to be “dour” and “melancholy.” And she is still, and probably always will be, a worrier."

- Kim B.


Insightful Comments

I believe that anxiety is more a result of one's environment rather than genetics.  I am basing my position on personal experience and behavior as well as observing others and not on years of formal research.  I certainly would concur that genetics has an impact on every part of a person’s development. However, I also believe that environmental influences have just as much weight on the development and personal growth as the genetics.

Genetics cannot be discounted, and it should certainly be researched in conjunction with our physical and mental make-up. Genetics often predestine us to certain physical attributes or diseases.  Meanwhile, environmental influence contributes as much to our personal growth and a great percentage to our life and understanding of who we are or who we may become.  For example, think about a child that is adopted and raised away from the biological family. The child will adapt to and adopt most of their behaviors and beliefs from those that have the greatest influence on their life - Their adoptive parents.

The reality exists that they could have similar physical ailments that attributed to their biological parents, where the child could suffer from the same form of cancer, diabetes, or perhaps even mental disorders. With the absence of physical presence or specific environmental influence in/on the life of a child, there can be little to no other explanation, other than DNA, for the appearance of disease or disorder in the child’s life.

Indeed there have been famous studies on the use of touch and the denial of touch on babies and the affects on personal growth of both control groups. As human beings we crave the touch and presence of others in our lives. This example is based solely on environmental influences and factors.

We have often seen case studies on the influence of people on their peers. Young people, especially crave acceptance. They are more likely to compromise who they are or what they believe in order to be accepted. In so doing they will inhibit their personal growth along the way. This creates anxiety in and of itself. This anxiety is manifested through a conflict of their identity.

Which brings us to the ultimate anxiety issues that we face in our identity crisis. Who are we? Whose are we? Where do we belong? Why are we here?  The question, is anxiety more influenced or affected by environmental factors or genetics?  My answer is yes.

I believe that environmental factors have a greater influence than a person’s genetic make-up. However, I also believe there is considerable evidence to argue both positions in an intelligent and informed manner.

I recall a young man that grew up in a home with an extreme drug and alcohol-addicted mother. His mother pursued a career as a stripper, which helped her to further spiral into a world of despair. His older sister unfortunately followed in her mother’s footsteps in both her occupation and chemical habits.

This young man loves his mother and his sister, but he did not follow their path. It would have been easy, but he resisted both the genetic bonds and the environmental influence. He graduated high school, joined the military, and began collegiate studies, and focused more on his personal growth than being swept into the wave of despair that claimed both his mother and his sister.

He has and still is overcoming.

- Bergen

References

Henig, R. (2009, October 3). Understanding the Anxious Mind. Retrieved December 28, 2014, from http://www.nytimes.com/2009/10/04/magazine/04anxiety-t.html?pagewanted=all