Stress

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Chapter 16

• Stress

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Alcohol, Tobacco, Bad Food

• The beginning of the chapter spends a great deal
  of time
• giving facts and statistics concerning a variety
  of unhealthy
• behaviours that humans engage in.
• I will briefly discuss these in two groups, with
  the purpose of
• making some conceptual points I think are
  important
• Dont these behaviours defy evolution?
• Why are humans getting fatter?
• Short-term gain vs. long-term pain

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Dont These Behaviours Defy Evolution?
Many of the behaviours in question genuinely
threaten the persons ability to survive a long
life. At the face of it, one would think that if
the principles of evolution were correct, our
species should have selected against such
behaviours long ago. However, in virtually all
cases, the behaviours do not pose a problem until
after the individual has passed their
prime reproductive years. Given this, while the
behaviours may harm the individuals life
expectancy, they do not interfere with their
reproductive success.
4
Why are Humans Becoming Fatter?

• One of the biggest problems shared by virtually
  all humans
• is that we eat too much fat - Figure 16.1
• There is no doubt that we are all drawn towards
  sweets and
• high fat foods. There are good evolutionary
  reasons for this
• Sweet foods are seldom poisonous
• High fat foods were rare, but calorically
  efficient.
• We also (as cave people) used to naturally
  exercise a great
• deal in our day-to-day lives. However, modern
  conveniences
• have reduced this natural exercise that our
  machinery is based
• on without adding exercise we store too much
  fat.

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Short-term Gain vs. Long-term Pain
Another factor that seems to support many
unhealthy behaviours is the tendency we as
humans have to favour short-term rewards in the
face of long-term punishments. For example, when
someone smokes as a teen, there are a variety of
rewards for doing so from physiological
rewards (a nicotine hit) to social rewards
(fitting with the group). These rewards are
seemingly more salient to us, even when we know
the long-term effects (dying of cancer). Similar
explanations could also be provided for unsafe
sex, substance abuse, and eating too many
unhealthy foods.
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Stress and Health
Stress is a pattern of physiological,
behavioural, emotional and cognitive responses to
stressors. Stressors are stimuli that are
perceived as blocking a goal or endangering or
otherwise threatening our well-being. Stress is
thought to be an extremely adaptive response
that helps us and our ancestors prepare to fight
or flee in the face of danger. Temporarily
experiencing stressors may be OK or
even desirable. But long-term exposure seems to
have negative effects on both our physical and
psychological health.
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General Adaptation Syndrome
Much of what we know about the effects of stress
come from the work of Hans Selye, a Canadian
eh! He found that prolonged exposure to stress
causes physiological reactions that fall into
three stages Alarm Upon first encountering a
stimulus, the entities resistance to the stressor
may drop below normal, causing impaired
physiological functioning - shock Resistance
This reflects the organisms adaptation to
the stressor the physiological system goes back
to normal levels. Exhaustion With prolonged
exposure, the physiological system stops
resisting and goes way below normal.
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Pictorially
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Exhaustion and Health
When the physiological system reaches the point
of exhaustion, it is weak and susceptible to
health problems. Thus, continued exposure to
stressful situations causes health problems,
physical and psychological. Why would we have
evolved a stress-management system that works
in this manner? Quite simply, we have because
survival stressors, the ones we assume formed
our machinery, tend to be short-term in nature
thus the system has been built to handle
short-term stressors, not long-term stressors.
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Stress and your Skin?
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A Role for Cognition
In the definition of a stressor, we said it was a
stimulus that was perceived to be
dangerous. This suggests that the manner in
which a person views a stimulus may effect the
extent of stress reaction it causes. One theory
of this, called cognitive appraisal, suggests
that when a stimulus comes up we first assess
whether it is dangerous then, if it is, we see
if we have the resources to deal with it. Only
dangerous things we cannot deal with cause
stress. A second factor that appears critical is
our ability to control the stressor a stressor
we can control is less stressful that one we
cannot control.
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Cognitive Appraisal
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Coping with Stress
Given that cognition can affect stress reactions,
it should not be surprising that we can learn
better ways to deal with stress. These ways to
deal with stress are termed coping
strategies which are defined as a plan of action
we follow, either in anticipation of encountering
a stressor or as a reaction to it, that is
effective in reducing the level of stress we
experience. These fall into two general
categories Problem-focused aimed at the
source of the stress taking courses that
will help you avoid stress at work. Emotion-focu
sed aimed at the stress reaction learning to
relax, or seeking support from friends.
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Dealing with StressEmotion Focused Therapies
People who regularly engage in aerobic exercise
deal better with stress than those who do not.
Why? Perhaps the increased air makes them feel
better, perhaps it is a control
issue. Sometimes, cognitive reappraisal of a
stressful stimulus as less stressful may also
help e.g., nerves as energy. Relaxation
training is another very useful method for
learning to deal with stress kind of the new
count to ten method.
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Links for those who want more stress
For more stress theory http//mentalhelp.net/
psyhelp/chap5/chap5o.htm With respect to stress
and health http//www1.od.nih.gov/obssr/stres
imm.htm Smoking and health
http//www.cs.brown.ed/lsh/docs/health.html Alco
hol and health http//www.powerup.com.au/md
avey/alcohol.htm