Genes play a role in how people respond to stress. A study found that genetic factors were responsible for 32% of differences in perceived job stress, 35% of differences in job satisfaction, and 47% of differences in health problems. Personality traits like optimism are also influenced by genetics and impact how people experience stress. Studies with monkeys found that immune systems and gene expression changed depending on social rank, showing rapid genetic responses to stress. Research on genes associated with anxiety, PTSD, and the stress response help explain individual differences in vulnerability to stress-related disorders.

1. Genes and Stress
The Psychology of Stress
Webster University

2. Genes and Stress
• According to a study of Swedish twins, the
relationship between job stress and health
problems is influenced in part by differences in
personality and temperament, such as how
optimistic, confident or self-critical a person is.
• And these traits are in turn closely related to
genetic makeup.

3. Study cont’d
Researchers made two initial conclusions:
1. Personality type is associated with job stress
and health
2. A large portion of the differences in personality
type -- nearly 45% -- can be attributed to
genes.

4. Study cont’d
• Researchers estimate that genetic effects are
responsible for …..
▫ 32% of the person-to-person variance in job stress
▫ 35% of the variance in job satisfaction and
▫ 47% of the variance in health problems.

5. Type A
• Type A individuals tend to be very competitive and self-
critical. They strive toward goals without feeling a sense
of joy in their efforts or accomplishments.
• Inter-related with this is the presence of a significant life
imbalance. This is characterized by a high work
involvement.
• Type A individuals are easily ‘wound up’ and tend to
overreact.
• They also tend to have high blood pressure
(hypertension).

6. Types
• Type A behavior: competitive, ambitious,
impatient, aggressive, fast talking.
• Type B behavior: relaxed, non-competitive.
• Type C behavior: ‘nice,’ hard working but
become apathetic when faced with stress

7. Monkey study
• To test how gene expression would differ when a
monkey's rank changed, the scientists at Yerkes
took the female macaques from their native
groups and constructed 10 new social units,
where rank was determined based on how early
a female was added to her unit.

8. Study cont’d
• Researchers then took blood samples from the
monkeys and isolated the white blood cells.
• The results show that lower-ranking monkeys
had lower levels of a certain kind of T cell and
showed signs of exposure to chronic stress
• Two findings that helped explain why their genes
turned on and off differently than high-ranking
monkeys.

9. Monkey study
• The females' immune systems responded rapidly
when they moved from a lower social rank to a
higher one, to the point where formerly low-
ranking animals looked genetically like high-
ranking ones.

10. More research
• When we are stressed, it sets off a chain reaction
of chemical signals in our bodies. The first of
these is the release of a chemical called serotonin
in the brain — something that happens as soon
as we get yelled at by our boss, for example, or
get cut off in traffic.
• This release of serotonin lights the fuse for the
explosive cascade of chemicals that follows,
eventually leading to increased levels of cortisol
in our system.

11. Stress
• What this gene mutation does is produce a
slightly different serotonin receptor in the brain
— one that causes an even greater than normal
release of cortisol in response to stress.

12. Cortisol link
• This is bad news for our hearts. Specifically,
increased cortisol has been shown to be
associated with higher levels of calcium deposits
in the heart’s blood vessels, and blockage of
these vessels is linked to increased risk of heart
attack and death.

13. Research
• Friedman & Rosenman (1959) (both cardiologists)
found that people with type A personality run a higher
risk of heart disease and high blood pressure than type
Bs.
• Their theory was based on an observation of the patients
with heart conditions in their waiting room.
• Unlike most patients, who wait patiently, some people
seemed unable to sit in their seats for long and wore out
the chairs.

14. Diathesis-stress model
• The diathesis-stress model is a psychological
theory that attempts to explain behavior as a
predispositional vulnerability together with
stress from life experiences.

15. Diathesis-stress model
• The diathesis, or predisposition, interacts with
the subsequent stress response of an individual.
Stress refers to a life event or series of events
that disrupt a person’s psychological equilibrium
and potentially serves as a catalyst to the
development of a disorder

16. Diathesis
• Some examples of diatheses include genetic
factors, such as abnormalities in some genes or
variations in multiple genes that interact to
increase vulnerability.
• Other diatheses include early life experiences
such as the loss of a parent.
• Diatheses can also be conceptualized as
situational factors, such as low socio-economic
status or having a parent with depression.

17. PTSD research
• Participants carrying two copies of one variant
within the PRKCA gene, dubbed the A allele,
remembered the most details about the pictures.
• Those carrying two copies of the other variant —
the G allele — remembered the least, with the
performance of those carrying one copy of each
variant lying somewhere in the middle.

18. PTSD research
• The researchers finally examined the
distribution of the A allele in a group of 347
survivors of the 1994 Rwandan genocide who
had fled the civil war and were living in a
Ugandan refugee camp.
• All had experienced multiple traumatic events
during the civil war, but only 134 of them had
been diagnosed with PTSD.

19. PTSD research
• “The A allele was significantly over-represented
in those with a diagnosis of PTSD
• Carriers of this allele had a roughly 2-fold
increase in risk for PTSD.”

20. Anxiety research
• Studies in the past ten years have identified
genetic profiles associated with common anxiety
disorders, like Generalized Anxiety Disorder
(GAD), Social Anxiety Disorder (SAD), Panic
Disorder (PD), and Obsessive Compulsive
Disorder (OCD).
• There’s not one specific gene that causes anxiety,
but combinations of genes seem to be at play.

21. Anxiety research Cont’d
• In late 2007, Yale researchers published a study
identifying a gene variation associated with
chronic worry and overthinking (what they call
“rumination”).

22. Anxiety research
• Last year, a team at Massachusetts General
Hospital found a gene variation associated with
SAD. Findings like these would explain why
children of a parent with SAD are two to three
times more likely to have the disorder; children
of a parent with panic disorder are up to eight
times more likely to exhibit PD.