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1-Evolution of Love
2-Physical and Emotional Cost of
Anxiety Disorders
3-Substance Abuse in Adolescents by
Elahe Sagart, M.D.
4-The
Effects of Substance Abuse on Brain by Nader Oskooilar, M.D.
Evolution of
Love
By: Nader Oskooilar, M.D., Ph.D.
“Nothing in biology
makes sense except in the light of evolution.”
Dobzhansky T. American Biology Teacher, 35: 125-129. 1973.
“Nothing in psychology
and psychiatry makes sense except in the light of
evolution.”
Nader Oskooilar
Meaning of Life
“All attempts to account
for the meaning and reason for life on earth before 1859”, when Darwin’s
The Origin of Species was published, “are worthless and that we will be
better off if we ignore them completely.”
Simpson GG.
The biological nature of man, Science, 152: 472-8, 1966.
Meaning and reason for
life, before 1859, was based on: theory, philosophy, intuition, bias,
superstition, fantasy, wishful thinking, illusions, delusions, faith,
and the like. None were based on credible evidence. Evolution was the
first theory that was backed by scientific evidence.
Selfish Gene
Selfishness in living
beings amounts to selfishness at the levels of genes to duplicate
themselves. The argument is that we, and all other animals, are machines
created by our genes. This gene selfishness will usually give rise to
selfishness in individual behavior. However, sometimes a gene can
achieve its own selfish goals best by fostering a limited form of
altruism at the level of individual animal. Much as we might wish to
believe otherwise, universal love and the welfare of the species as a
whole are concepts which simply do not make evolutionary sense.
Dawkins R. The
Selfish Gene (3rd 30th anniversary edition). Oxford University
Press, New York, 2006.
What are the evidences for evolution?
The evidence for evolution is
now quite overwhelming. Evolution is not a theory anymore. It is a fact.
1-The Fossil Record
2- Common Descent and
Branching Evolution
3- Morphological
Similarity
4- Embryology
5-Vestigial Structures
6- Biogeography-
Molecular Evidence
There is no other
natural explanation than evolution for the facts presented here.
Love
“Love is everything
it’s cracked up to be…. It really is worth fighting for, being brave
for, risking everything for. And the trouble is, if you don’t risk
anything, you risk even more.”
Jong, E. How to Save
Your Own Life.
Being ‘in love’ is a
physiological phenomenon that may have evolved to facilitate pair
bonding for the purpose of conceiving children and nurturing them in the
first few months or years of life. In most cases, passionate love
feelings fade within a few months to a few years, rarely lasting more
than three years. This might be why the most common time for divorce is
in the fourth year after marriage. The obsessiveness, infatuation,
delusion-like bias, and euphoric episodes subside and the lover’s
negative traits become more prominent and noticeable.
A deeper, more lasting
bond may develop between the two individuals, and the relationship may
continue to deepen through the years. But in these cases, the ‘blind’
love appears to be replaced by a different type of bond. It is not
delusional and obsessional, but it involves feelings of intense loyalty
and affection, the tendency to see the other in more positive than
negative light, and strong possessiveness, protectiveness, and jealousy
of the other’s affection. This type of bonding affords the opportunity
to raise children until they are sexually mature or older.
Both types of pair
bonding (short and long) confer a different type of evolutionary
advantage.
Mating and Reproduction
Darwin saw that the
preferences of female animals for certain characteristics in males were
directly parallel to what humans do in the selective breeding of
animals. Under female mate choice, characteristics preferred in a mate
would become more pronounced over evolutionary time. Female choice could
select for behavioral potentials such as intelligence or an inclination
for nurturance on the part of the males.
Any heritable trait
that helps in competing for mates will tend to increase in frequency and
diffuse through the populations even if they compromise individual
survival. That is because, according to Darwin, evolution was a matter
of differential reproduction rather than differential survival.
Why have humans evolved
such costly and complex brains? Evolutionary psychologist Geoffrey
Miller suggests that the reason might lie in what he considers to be
Darwin’s most significant contribution to evolution:
sexual selection. Sexual selection is different than natural, or
“survival” selection, which refers to environmental factors such
as climate or predators that affect reproductive success. Sexual
selection is much more direct and potentially powerful; it is shaped by
the mate preferences of the opposite sex. For these reasons, Miller
believes that the inherently awesome power of sexual selection has
profoundly affected the equally awesome trajectory of our own species
mental evolution through mate choice.
This theory states that
human language abilities evolved very quickly as a result of runaway
sexual selection where females came to select males on the basis of
their language abilities. Through this mechanism, females were also
selecting males with high levels of intelligence.
The slow pace of
natural selection, according to this view, cannot account for the rapid
brain evolution and behavioral sophistication (including creative and
artistic abilities) in our species.
Preferences
of Men
Mate preferences and
mating strategies will vary depending on whether an individual is
pursuing a short-term mate or a long-term mate. Both men and women
engage in these two types of mating strategies, but for somewhat
different reasons. Ultimately both short-term and long-term mating
strategies increased the reproductive fitness of our species.
Because of the nature
of male reproductive physiology, men can potentially greatly enhance
their reproductive fitness by impregnating as many different women as
possible. The best method to achieve this end is short-term mating
strategy. One result of this strategy is that a man’s standards
regarding mate choice should be greatly relaxed.
In this regard, male’s
long-term mating preferences are a complete reversal of their short-term
preferences where highly promiscuous women are favored. A potential
long-term mate should display indicators of good parenting skills or
high level of nurturance. They also need to show indicators of health,
fertility, and overall genetic quality.
In a study of 37
cultures, it was found that men rated kindness, understanding,
intelligence, and physical attractiveness as the top qualities they
valued in a potential long-term mate. Exciting personality, good health,
and adaptability were also high on the list. This list was very close to
the list of long-term mate preferences by women, with exception of two
qualities that men universally desired more. They were a partner younger
than them and physical attractiveness
Preferences of Women
Short-term mating in
women can be viewed as a sort of “shopping around” behavior. It allows
her to assess a number of potential male mates and to clarify more
precisely which traits are more important to her in a long-term mate.
Furthermore, in the process she is able to hone her own skills for
acquiring and keeping a long-term mate. A second reason for pursuing a
short-term mating strategy would be that a woman could obtain immediate
resources in exchange for short-term mating. Another reason would be to
improve the genetic quality of her offspring. By mating with someone
other than her long-term mate a woman could potentially produce children
with better genetics. Short-term mating could also provide the first
step in mate-switching process or a sort of back up in case the
long-term mate left or was killed.
Studies found that
women were twice as likely as men to demand long-term pair bonds
including marriage, which they preferred to men by a factor of four.
Women weigh status and wealth in short-term mates much more than in
long-term mates. In short-term mating, women have a strong preference
for extravagance and the availability of immediate resources and
strongly dislike stingy men. The extra resources acquired in this manner
would have given ancestral women obvious fitness advantages. Women also
place a greater premium on physical attractiveness in short-term mating
relationships (to improve the genetics of their offspring).
Evolution predicts that
the long-term choices of females will be based on criteria that will
facilitate the survival of their offspring. Women not only prefer men
with resources but also show a preference for characteristics indirectly
related to resources, which include social status, ambitiousness, and
industriousness. They also prefer men older than themselves.
The Aesthetics of Attraction
Exactly what constitutes
physical attractiveness?
Evolutionary psychology
predicts that aesthetic judgments are based on decisions that relate
directly to survival and reproduction, and not necessarily on cultural
influences and arbitrary individual tastes.
Empirical findings show
that although there is individual and cultural variation in aesthetic
judgments, the underlying core (aesthetic sense) is a product of eons of
natural selection. Examples:
A- Mate choice in a
variety of species including humans appears to be based in part upon
assessments of body symmetry. High levels of symmetry are thought to be
indicative of high levels of developmental precision. Consequently, an
organism that displays high symmetry can be inferred to possess good
genes that are resistant to disease, parasites, and developmental
irregularities. For example, studies have shown that composite faces
that were produced by computer averaging hundreds of individual faces
were perceived as more attractive than individual faces because they
were more symmetrical. In another study, a significant negative
correlation was found between the self-reports of orgasm in females and
the measures of asymmetry of their partners. One function of female
orgasm might be to take up sperm into the cervix via the spasmodic
contractions that occur. A different study revealed that women engaged
in extra-marital affairs were more likely to have affairs with more
attractive partners than their long-term mate. They were also more
likely to have the affairs around the time of their ovulation, and
reported more orgasms than when copulating with their regular partner.
Female orgasm can be viewed as physiological mechanism to
promote fertilization from some mating partners over others.
This sort of mixed
reproductive strategy in females (long-term relationship with a
committed man and short-term affair by with males of high genetic
quality) may be a consequence of the fact that highly symmetrical males
have greater mating opportunities with large numbers of women and may be
less likely to invest in one particular female.
B- Waist-Hip Ratio. One
highly reliable indicator of a woman’s health and fertility is her
waist-hip ratio. Biomedical studies indicate that this ratio reliably
signals female reproductive status, reproductive capability, and health
status in women. The typical range is 0.67-0.80 for women and 0.80-0.95
for men. The differences of “android fat” and “gynoid fat”. Data from
Miss America winners from 1923-1987 show a range from0.69-0.72. For the
centerfolds of Playboy over the years, there was a trend toward greater
slimness, but the WHR remained virtually the same. Even the fashion
model Twiggy, had a WHR of 0.73.
Men ages 25-83, from
different cultures, in a wide range of professions, income levels, and
life experiences, given a chance to rate the attractiveness of a series
of line drawings of women, consistently chose the figure with a 0.70 WHR
as their favorite. Even in underweight and overweight figure categories,
0.70 WHR was still the preferred.
Women generally
preferred men to have a WHR of 0.90 and to be within the normal weight
range. Income and occupation of men had as much weight as their WHR.
Jealousy and Mate-Guarding
Jealousy could be defined as
a fear and rage reaction fitted to protect, maintain, and prolong the
intimate association of love. Jealousy is a logical prediction from
evolutionary theory. In fact, if jealousy did not exist as a universal
human characteristic, it would represent an oddity that demanded
scientific explanation.
In males, jealousy
resolves around the issue of uncertainty of paternity. It is an adaptive
response in men to help insure certainty of paternity. Male jealousy is
more concerned with sexual infidelity and female jealousy with emotional
infidelity. In women jealousy functions to help insure continued
investment from a mating partner.
Jealous competition in
behavior of humans is also present at the physiological level by sperm
competition. In species where insemination by a rival is a possibility
(chimpanzee) there is a large volume of ejaculate produced. A high
percentage of this ejaculate is, moreover, infertile, its primary
function being to block or destroy sperm that has been injected by a
rival. Human sperm has these general characteristics. Women also show a
capacity for mate choice at the physiological level. This is the issue
of orgasm discussed earlier.
References
1- Palmer JA, and
Palmer LK. Evolutionary Psychology: The Ultimate Origins of
Human Behavior.
Allyn and Bacon, Boston, 2002.
2- Mayr E. What
Evolution Is. Basic Books, New York, 2001.
3- McGuire MT, and
Troisi A. Darwinian Psychiatry. Oxford University Press,
New York, 1998.
4- Stevens A, and Price
J. Evolutionary Psychiatry: A New Beginning (2nd
edition). Brunner-Routledge,
Philadelphia, PA, 2000.
5- Buss DM.
Evolutionary Psychiatry: The New Science of the Mind
(2nd
edition). Allyn and Bacon, Boston, Mass, 2003.
6- Dobzhansky T.
Nothing in biology makes sense except in the light of
evolution.
American Biology
Teacher, 35: 125-129. 1973.
7- Simpson GG. The
biological nature of man, Science, 152: 472-8, 1966.
8- Darwin CR. The
Origin of Species. John Murray, London, 1859.
9- Dawkins R. The
Selfish Gene (3rd 30th anniversary edition).
Oxford University
Press, New York,
2006.
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Physical and Emotional Cost of
Anxiety Disorders
Stress could be
defined as anything (real, symbolic, or imagined) that threatens an
individual’s well-being and survival. Stress can be physical (physical
trauma) or emotional (anxiety, fear, depression). Not all stress is
necessarily harmful. For example, physical stress such as exercise could
be beneficial, especially if it is not severe or excessive and the
person does not suffer from significant health problems such as heart
disease. Much is known about physiological response to acute stress but
considerably less is known about the response to chronic stress.
When under stress, our
body activates a large number of biological mechanisms that seek to
diminish the impact of the stressors and restore balance. Intense or
perpetual stress, however, may tax a person’s physiological and
psychological resources and harm the brain and its functions and damage
the body.
The body responds to
stress mainly through two channels: neuronal and hormonal-they are
closely interconnected. The former is principally by means of the
sympathetic branch of the Autonomic Nervous System (ANS) and the latter
via the hormones secreted by the adrenal, pituitary and thyroid glands.
The ANS effect is mainly bodily functions instantly and directly, while
hormones have slower yet wider effect on the body. Each system has
beneficial effects and is preventive in times of acute stress. But they
can be detrimental if they are active chronically (such as in anxiety
disorders).
When people
perceive that they are in threatening situations that they are unable to
cope with, then messages are carried along neurons from the cerebral
cortex (where the thought processes occur) and the limbic system
(emotional centers) to the Hypothalamus. The Anterior Hypothalamus
produces sympathetic arousal of the Autonomic Nervous System (ANS). The
ANS consists of two different systems: the sympathetic nervous system
and the parasympathetic nervous system. Essentially, the parasympathetic
nervous system conserves energy levels. Unlike the parasympathetic
nervous system, which aids relaxation, the sympathetic nervous system
prepares the body for action. In a stressful situation, it quickly does
the following:
-
Increases
strength of skeletal muscles
-
Decreases
blood clotting time
-
Increases
heart rate
-
Increases
sugar and fat levels
-
Reduces
intestinal movement
-
Inhibits
tears, digestive secretions.
-
Relaxes the
bladder
-
Dilates pupils
-
Increases
perspiration
-
Increases
mental activity
-
Inhibits
erection/vaginal lubrication
-
Constricts
most blood vessels but dilates those in heart/leg/arm muscles
If the person perceives
that the threatening situation has passed then the parasympathetic
nervous system helps to restore the person to a state of equilibrium.
However, for many people they perceive everyday of their life as
stressful. Unfortunately, the prolonged effect of the stress response is
that the body's immune system is lowered and blood pressure is raised
which may lead to essential hypertension and headaches. The stress
response also includes the activity of the adrenal, pituitary and
thyroid glands.
The two adrenal glands are located one on top of each kidney. The middle
part of the adrenal gland is called the adrenal medulla and is connected
to the sympathetic nervous system by nerves. Once the latter system is
in action it instructs the adrenal medulla to produce adrenaline and
noradrenaline (catecholamines), which are released into the blood
supply. The adrenaline specially prepares the body for fight or flight
response. It increases both the heart rate, and the pressure at which
the blood leaves the heart; dilates bronchial passages and dilates
coronary arteries; skin blood vessels constrict and there is an increase
in metabolic rate. Also gastrointestinal system activity reduces which
leads to a sensation of butterflies in the stomach. Heart rate and
breathing rates are increased, blood pressure is elevated, stomach might
become queasy, strength is augmented, senses such as vision (pupils
dilate) and hearing are heightened, and there is dry mouth, nausea,
sweating, and sudden feelings of abject terror and helplessness.
Finally, there is thickening of blood- to increase oxygen supply (red
cells), enabling better defense for infections (white cells) and to stop
bleeding).
Lying close to the hypothalamus in the brain is an endocrine gland
called the pituitary. In a stressful situation, the anterior
hypothalamus activates the pituitary by secreting a substance called CRF.
The pituitary releases adrenocorticotrophic hormone (ACTH) into the
blood, which then activates the outer part of the adrenal gland, the
adrenal cortex. This then synthesizes cortisol which increases arterial
blood pressure, mobilizes fats and glucose from the adipose (fat)
tissues, reduces allergic reactions, reduces inflammation and can
decrease lymphocytes that are involved in dealing with invading
particles or bacteria. Consequently, increased cortisol levels over a
prolonged period of time lowers the efficiency of the immune system. The
adrenal cortex releases aldosterone, which increases blood volume and
subsequently blood pressure. Unfortunately, prolonged arousal over a
period of time due to stress can lead to essential hypertension.
Accumulating research indicates that constant or intense stress may
sometimes negatively influence the brain and its functions. Stress may
alter brain cells, brain structure and brain function. As a consequence,
memory problems and some psychiatric disorders such as depression may
erupt. Under stress, extensions of brain cells, known as dendrites,
wither in the hippocampus, a brain area important for memory. Stress can
also diminish the naturally occurring replacement of brain cells in the
hippocampus, one of the few brain regions that can produce nerve cells
throughout life. People with Cushing’s syndrome produce massive amounts
of the stress hormone, cortisol, making them a good model of what may
occur when the stress system is put on override. Individuals with
Cushing’s have memory problems and smaller than normal hippocampus.
Research also reveals
relationships between severe or chronic stress and psychiatric ailments
such as PTSD (posttraumatic stress disorder) and clinical depression.
For example, measures of stress chemicals indicate that the stress
system sometimes is overactive in some people with these ailments.
Individuals with chronic or recurrent clinical depression or with PTSD
may have a smaller hippocampus and experience memory problems. Also, it
has been shown that chronic depression leads to scarring in brain that
interferes with normal functioning of the brain.
Part of stress response
also consists of inhibition of immune system by glucocorticoids. Again,
this action might be beneficial to the body in the short run, to be able
to attend to the urgent business of fight or flight. But in the long run
(chronic stress), it can disrupt and weaken the immune system of the
body and make one potentially more susceptible to infectious diseases
and even to cancer.
The pituitary also
releases thyroid stimulating hormone, which stimulates the thyroid
gland, which is located in the neck, to secrete thyroxin. Thyroxin
increases the metabolic rate, raises blood sugar levels, and increases
respiration/heart rate/blood pressure/and intestinal motility. Increased
intestinal motility can lead to diarrhea. (It is worth noting that an
over-active thyroid gland under normal circumstances can be a major
contributory factor in anxiety attacks. This would normally require
medication.)
Fair amount of
circumstantial evidence indicate that emotional stress can be associated
not just with psychiatric disorders but also with physical ailments such
as with heart disease and early death. Evolutionary speaking, emotional
stress might have been protective. But in modern times, the adrenaline
surge is not channeled into rightful conclusion (fight or flight).
Instead of being released in a burst of physical exertion, it is
internalized. Surge in adrenaline, especially on a chronic basis, causes
blood to clot more readily, increasing risk of heart attack. It can also
constrict the coronary arteries so that blood flow to the heart muscle
is reduced.
Type of emotional stress
is important. For example, people with little control fare worse than
ones with control. Examples are secretaries vs. bosses, children vs.
controlling adults, and spouses in abusive relationships. If some sense
of control over one’s destiny is maintained, stress can be exhilarating
rather than debilitating (e.g., entertainers and politicians).
Anxiety disorders are
among the most prevalent psychiatric conditions in the United States and
they are a major source of stress for patients who suffer from them.
They produce inordinate morbidity and functional impairment. One in four
people have at least one anxiety disorder during their lifetime. These
disorders (e.g., Generalized Anxiety Disorder, Panic Disorder, Social
Anxiety Disorder, Obsessive Compulsive Disorder, and PTSD) are usually
chronic stressors with unknown or multiple possible etiologies. There is
no doubt that abnormal genes predispose to pathological anxiety states.
But evidence also indicates that traumatic life events and stress are
also etiologically important.
.
Treatment is usually
very effective for anxiety disorders. Some people are afraid to take
medications for anxiety disorders, thinking that medications are
dangerous for their brain and body. The reality is usually quite the
opposite. Chronic anxiety disorders are detrimental to health; people
might have more health problems and shorter lives, they suffer
extensively for years and decades, they are not functional and cannot
reach their potential, people around them suffer the consequences,
society pays a high price, and there is a great risk for developing
other disabling psychiatric disorders such as depression, alcohol and
substance abuse, and other anxiety disorders. The risks of untreated
anxiety disorders far outweigh the potential risks of available safe and
effective medications to treat anxiety disorders. Treatment improves the
quality of life, prevents further complications, and diminishes or
eliminates painful symptoms.
Available medications
are obviously not perfect; they do not work well for everybody, or are
not well tolerated by some people. That is why pharmaceutical companies
are attempting to develop other alternatives that might be more
effective and with less side effects. These medications have usually
been tested on animals, healthy volunteers and some patients. No safety
issues have surfaced and the drugs have shown some effectiveness by the
time they are approved for trial on larger number of patients with
anxiety disorders across the United States.
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