Biological Level of Analysis
2.1 Physiology and Behavior
First of all, the biological level of analysis argues that
there are physiological factors that affect behavior in organisms. It should be
noted, however, that physiology is not the only factor that impacts behavior.
The environment and cognition may interact with biological systems and affect
physiology. Biology can affect cognition, and cognition can equally affect
biology. (The two are bidirectional). The biological level of analysis takes on
a reductionist view - they believe that behavior is caused by biological
factors (e.g. hormones, neurotransmitters, etc.) This reductionist view is
often criticized for being overly-simplistic for explaining behavior.
<NATURE V.S. NURTURE EVENT>… "Is behavior a
result of biological factors or environment?"
(IB psychology takes on an interactionist approach: meaning
they do not rely solely on either biological or environmental factors)
- Outline principles that define the biological level of
analysis
1) Behavior can
be innate because it is genetically based (What you do naturally, on instinct.
This is a result of evolution)
2) Animal
research can provide insight into human behavior. This is why a lot of research
is done on animals.
3) There are
biological correlates to behavior - hormones, proteins, metabolism and
neurotransmitters are all known to affect the behavior of a person.
- Explain how principles that define the biological level of
analysis may be demonstrated in research (through theories or studies)
1) There are biological correlates
of behavior: Newcomer at al (1999) performed an experiment on the role of the
stress hormone cortisol on verbal declarative memory. Cortisol is a hormone
that is known to interfere with your memory. He collected a total of 51 people
for an experiment that tested memory and cognitive functions before and after
treatment of high doses or low doses of cortisol, or inactive substances
(=control substance). As a result of this experiment, Newcomer et al observed
that memory impairment happened only in the individuals who were treated with
high doses of cortisol, after only four days of exposure. However, the
researchers also found out that this memory loss was only temporary as after a
week of having a wash-out period, all the subjects’ memory performances
returned to their untreated levels. This experiment shows that there are
biological correlates to behavior – in this case, cortisol being a hormone that
affects the memory performance of an individual.
More on this experiment at: http://www.sciencedaily.com/releases/1999/06/990617072302.htm
(2) Animal research can provide
insight into human behavior: This means that researchers use animals to study human
physiological processes, because it is assumed that biological processes in animals
are the same, or similar as in humans. One important reason for using animals
is that there is a lot of research where humans cannot be used for ethical
reasons (such as hurting the subject). The use of animal research in order to
provide insight into human behavior can be demonstrated in the studies of Martinez
and Kezner (1991), where an experiment was carried out studying the role of
neurotransmitters in learning and memory. (This is an experiment that used
various chemicals to test acetylcholine, which is responsible for memory
retention.) The mice’s brains were altered and observed – the results were
generalized to humans as well.
(3) Human behavior innate, and thus
genetically based: Researchers interested in the genetic origin of behavior
often use twin studies so they can compare one twin with the other on a
variable such as intelligence, depression or anorexia nervosa. Bouchard et al
(1990) who performed the Minnesota twin study, a longitudinal study
investigating the relative role of genes in IQ. He found that IQ was affected
by environment, but also have genetic influences as well. This shows that some
behavior (such as a person’s intelligence) is innate (such as in one’s genetic
material).
- Discuss
how any why particular research methods are used at the biological level of
analysis
- Discuss
ethical considerations related to research studies at the biological level of
analysis
Laboratory experiments: At
the biological level of analysis, lab experiments are commonly used to establish
cause and affect relationships between the variables that are being studied. A
key point at this level of analysis is the use of animal experiments as well as
human experiments. When researchers want to test the degree of changes to
physiology (i.e. by injection of neurochemicals or hormones) or to test the
effectiveness of a new medication, lab experiments are used. Ethical
considerations should always be made; when the researchers are testing new
medications, the results are unpredictable - the patient's health and well-being
cannot be guaranteed. The patients should be fully aware of the study they are
taking part in. Their personal identities should also be protected. Using ‘codes’
or listing the patients as ‘anonymous’ will help protect the patient’s
identities. Laboratory experiments are useful because they allow the researchers
to make accurate conclusions and establish clear cause and effect
relationships.
Case Studies: The case study
is another way to carry out research on human participants, as well as on
animals. Instead of causing some kind of change to a person’s physiology,
researchers can take advantage of naturally occurring irregularities (e.g. SEVERE
brain damage or long term drug use) by obtaining detailed information about the
participant’s condition. As this approach is mostly descriptive, there is
relatively little harm that can be done to participants. This means that there
are less ethical concerns that in lab experiments – the irregularities are
present before the researcher studies the subjects. The most important ethical concerns
for case studies are the depth of information that the researcher has access to
and the researchers' steps to protect subject anonymity. The depth of
information affects the subjects because the information has the potential to
affect their daily lives. For example, if they are notified by the researcher
that they have a mental disability, this could harm the subject’s self-esteem
or confidence. Presenting or revealing the true names of the participants could
harm their chances of living normal lives – getting jobs, for example. Thus,
using pseudonyms or ‘anonymity’ is an acceptable way to protect the subject’s
privacy.
- Explain one study of localization of function of the brain
Paul Broca (1861) was a
psychologist who carried out a longitudinal study of a specific case where a
patient was unable to speak, but could understand conversations. This patient
was named Tan for he was unable to say anything except for the word 'tan'.
Although he was mute, he was able to understand simple conversations. After
Tan's death, Broca performed an autopsy and found that the left frontal lobe of
Tan's brain was severely damaged. Broca came to the conclusion that the brain
was localized - specific parts of the brain performed particular tasks that it
was specialised to perform. Broca hypothesized that the left frontal lobe of
the brain was responsible for tasks such as producing speech (locution) as well
as deducing meaning from complex language, emotions, and analysis of syntax. Broca
was one of the first psychologists to suggest that the brain was localized.
- Explain, using examples, functions of two hormones in
human behavior
Hormones are a class of chemicals
that affect behavior. They are produced by the glands that make up a system
separate from the nervous system called the endocrine system. Unlike
neurotransmitters, they are released into the bloodstream so they take a longer
amount of time to produce changes in behavior, but are longer-lasting than
neurotransmitters.
1-
Oxytocin is a hormone that is created by the hypothalamus after being
stimulated by the pituitary gland. It is a hormone that is released by touches
and hugs, and is associated with bonding between a mother and her child as well
as between lovers. As a hormone, oxytocin plays a role by inducing labor
contractions and lactation. Oxytocin is thought to change the brain signals
that are related to social recognition via facial expression in the part of the
brain that is responsible for processing emotional stimuli (that is, the amygdala).
When oxytocin is injected into a healthy adult brain, the fear regulatory
circuits are affected and there is an increase in trust and generosity of that
person, so oxytocin is often called the love cocktail. Those who suffer from
social anxiety (that is, the inability to trust) might therefore benefit from
injection of oxytocin.
2-
Melatonin is another hormone that researchers think may help those with
insomnia or jet lag. The production of melatonin is stimulated by darkness and
is inhibited by light. Therefore, melatonin levels are high during the night
(peaks in the middle of night) and low during the day (gradually decreases
during the morning). Therefore, as winter approaches and the days become
shorter, this means that we are inclined to feel more tired earlier.
Melatonin is a hormone that
corresponds with the circadian rhythm (the internal 24 hour clock that we have
in our bodies) and it is suggested that taking melatonin early in the evening
helps one's ability to fall asleep. [However, if levels of melatonin are TOO
high, this could lead to lethargy and sleepiness: for example, the short days
of autumn and winter are known to affect the circadian rhythm of some people
and cause a form a depression. This depression is called SAD - seasonal
affective disorder. SAD is seen often in European countries with short hours of
light during the day in winter, such as in Scandinavia. ]
- Explain, using examples the effects of neurotransmission on human behavior
Nerve cells, also called neurons,
are the building blocks of behavior. These neurons send electrochemical messages
to the brain so people can respond to stimuli that is either external
(environmental) or internal (from internal changes of the body). The messages
that are sent are sent by a method called neurotransmission. When an electrical
impulse travels from the body of a nerve cell, it releases neurotransmitters
which then cross synapses between nerve cells. Neurotransmitters are natural
chemical messengers that transmit information from one nerve cell to another
nerve cell. (The neurotransmitters are stored in the nerve cell's terminal
buttons). After it crosses the nerve synapse, the neurotransmitters fit into
receptor sites on the post-synaptic membrane and the message of the
neurotransmitter is passed on. They can affect the mood, memory, sexual arousal
or mental illness of a person. Acetylcholine is a neurotransmitter that is
responsible for the development of memory, and serotonin is a neurotransmitter
that can make a person sleepy or emotional.
- Discuss two effects of the environment on physiological
processes
Page 46, brain plasticity: Before
the 1960s, it was believed that the makings and the functionality of the brain
was completely based on biological principles. However, Hubel and Wiesel (1965)
found that the brain is equally stimulated and affected by the environment of
which it is in. Hubel and Wiesel found that environmental enrichment can modify
the brain (cerebral cortex, specifically). The brain is constantly changing as
a result of experience and environment throughout the lifespan.
For example, brain plasticity is
the brain's ability to change in order to enhance or increase learning or
experience. The neural connections are remade and the structure of the brain is
changed. It changes due to the challenges of the environment – the brain adapts. Appropriate learning
and experience at certain times can increase the density of neural connections,
which in turn allow the brain to be capable to learn EVEN MORE. This
rebranching of neurons is called dendritic branching.
Rozenwig and Bennett (1972): researchers
placed two rats in different environments to study the effect of either
enrichment or deprivation on the development of neurons in the cerebral cortex.
The rat with a lot of toys to play with (thus, the “enrichment” group) was
found to have denser neural connections in the cerebral cortex. The rat with no
toys had no particular thickness of neurons in the cerebral cortex. Also, the
frontal lobes (which have to do with thinking) were heavier in the rats in the
stimulating (enriching) environment. Therefore, we can infer that environment
is a large factor that affects physiology.
*In other studies it was found that
the thickest cortexes are found within rats that were placed in stimulating
environments along with OTHER rats to interact with.
- Examine one interaction between cognition and physiology
in terms of behavior
Humans themselves are able to
change the functionality of the brain, as it was found in a study by Richard
Davidson (2004). Eight Buddhist monks who have been meditating for a long
period of their lives, and average adults who have trained in meditation for
100 hours were told to meditate on love and compassion. Using a PET scan,
Davidson found that the levels of gamma waves produced were increased in all subjects
during meditation. After meditating, he found that the monks' gamma wave
production did not end, while the average subjects stopped producing gamma
waves. (They had meditated on compassion for more than 10,000 hours in order to
gain the rank of adept). Also, the gamma-wave area was seen to be larger in the
monks than in the volunteers. Davidson argues that meditation can have
significant long term effects on the brain and how it processes emotions.
Therefore the brain can adapt to stimulation, either from external sources
(such as the environment) or internal sources (such as cognition).
- Discuss the use of brain imaging technologies in
investigating the relationship between biological factors and behavior
Modern technology is used often in
neuropsychology because it allows researchers to understand and study the
active brain. This in turn allows researchers to study the localization
functions of the brain. Researches before modern technology often included
invasive studies on animals, because animal researches allowed the brain to be
understood. However, these invasive techniques involved scarring and ablation
of brain tissue and parts of the brain, so there were extreme ethical concerns
with them. The behavior of animals before and after the lesioning was compared
and studied. In case of lesioning and scarring, the potential harm to animals
cannot be determined, and damage that is caused to the animals cannot be
reversed. This is a big ethical concern for animal research. The animals may
feel pain as well. This is why modern imaging technologies such as EEG, PET and
fMRI scans are popular and ethical ways of studying the brain and behavior.
The EEG is used by modern
researchers to study the brain. The EEG is a printout that shows 'brainwaves'.
The electrical charges of neural activity are shown in these printouts.
However, the EEG is not helpful for the fact that it does not show what is
happening in deeper brain regions, or the active functions of the brain.
PET scans monitor glucose
metabolism in the brain. A patient who is getting a PET scan is injected a
harmless dose of radioactive glucose, and its radioactive particles are
detected by the PET scan as it transfuses throughout the brain. This scan has
been used to detect tumors, changes in Alzheimer's and comparison of healthy
brains and brains with mental disorders. Gur et al found (1995) found more
active metabolism in the brain centers that control violence in men, than in
women. The largest advantage to a PET is that it can record current activity,
such as thinking.
fMRI scans provide 3D photos of
brain structures by using magnetic fields and radio waves. It shows actual
brain activity and can show active parts of the brain when it is engaged in
behavior. They have high resolutions and thus are easy to study and carry out.
2.2 Genetics and Behavior
- Outline principles that define the biological level of
analysis:
The biological principles that
define the biological level of analysis are: 1) that all behavior is correlated
to biological factors 2) animal researches can help researchers understand
human behavior 3) human behavior can be innate because it is genetically based.
The reason that we know that behavior has biological correlates is because we
have found that certain hormones and neurotransmitters can affect one's mood or
behavior. We know that animal researches are helpful to us to understand our
own physiology because brain structures are very similar across different
species. Finally, we know that behavior can be innate because evolution has
caused us to have intuitive knowledge and certain instincts, such as being
hungry.
- Explain how principles that define the biological level of
analysis may be demonstrated in research:
In the study of intelligence and inheritance
of intelligence, Scarr and Weinberg (1977) as well as Horn et al (1979) studied
parents who raised both adopted and natural children. It was assumed that all
the children involved in the study were brought up in the same environment, with
the same upbringing with the same parents. Therefore, it was also hypothesized
that any difference between the parent-child IQ correlations for adopted and
natural children should be attributable to genetics (ie genetic makeup or DNA).
However, the researchers found no significant correlations between the IQ of
the biological parents and the adopted children. This indicates that
intelligence could largely be affected by environment, rather than by nature
because the adopted children came from poor backgrounds with parents who had
considerably low IQ scores, while their adoptive parents were wealthy, white
and middle class parents with high IQ levels. Therefore, this study actually
contradicts the biological principle that 'there is always a biological
correlate to behavior' because this study supports the theory that intelligence
is affected by environmental factors rather than biological factors.
- Discuss ethical considerations related to research studies
at the biological level of analysis:
At the biological level of
analysis, particularly when studying genetics and behavior, adoption studies
are performed often to study and directly compare genetic and environmental
influences of behavior. Adoptive studies are studies where researchers try to
determine if genetics influence an adopted child's behavior (in relation to
their biological parents) or environment influences a child's behavior (thus
the adoptive or foster family). Other research methods on the biological
genetic level are twin studies and family studies. Twin and family studies
generally study how genetics (such as DNA) can influence behavior. Some ethical
considerations to make related to these types of genetic-biological researches
is to make sure none of the subjects are directly influenced by the study's
results. If a child who is adopted, but does not know so is involved in the
study for adoptive studies, then the research should be covert. If this child
were to find out that he/she was adopted without any prior explanation, then it
would naturally come as a shock to the child. The emotional or internal burden
that is a result of this would be a severe ethical concern.
- Discuss the extent to which genetics influence behavior
Genetic research in humans is
largely based on study types called correlational studies. This is when
researchers look at how different variables can co-vary. Therefore,
correlational studies establish new relationships between variables, without
the researcher manipulating any independent variables as they would do in an
experiment. This is why, unlike experiments, no cause and effect of variables
and factors can be determined in genetic research. Through these studies, such
as twin studies, family studies and adoption studies, researchers are able to
study the influences of genetics and the environment and determine the extent
to which genetics influences one's behavior. Researchers have concluded that
genetics does not completely dominate behavior, but many behaviors are
influenced in various ways by genetic-makeup.
- Examine one evolutionary explanation of behavior
Evolution affecting behavior is one
principle that is considered in the biological level of analysis. Darwin's
theory of natural selection is one evolutionary explanation of behavior. Darwin
states that members of a species (organisms) who have characteristics which
better suit the environment in which they live will be more likely to breed and
pass on their traits. This leads to evolutionary psychology, a field of
psychology that suggests that as genes are mutated, the advantageous genes are
passed on through the process of natural selection. Dan Fessler of the
University of California at Los Angeles (UCLA) carried out research on the 'disgust'
impulse in pregnant women. He found that the emotion of disgust has allowed our
ancestors to survive long enough to produce offspring, who then passed on the
same tendencies (the impulse of disgust) to us. According to Fessler, many of
the diseases that are most dangerous to humans are food-borne, and this is why
evolution and adaption has caused people (pregnant women especially) to have a
disgust-impulse towards food - to diminish the risk of illnesses and
infections. Overall, Fessler suggests that the view of disgust is a protection
against disease.
- Discuss ethical considerations in research into genetic
influences on behavior
Researches of human genetics focus
and identify particular genes that are involved in hereditary diseases. These
types of researches pose risks to participants because there is a link between
genetic heritage and people's lives. Sometimes the genetic information is
problematic for participants or their families (such as discovering a mental
illness) and it can be stigmatizing and affect people's abilities to get jobs
and insurance. In any study, participants should always understand their
privacy and confidentiality will be protected, and any genetic information that
is derived will be obtained as a part of the study. The aims and methods of the
studies should be explained in full detail to participants, and they should
sign a consent paper showing that they understand. Fully anonymizing the
samples of the genetic information would protect the identity of the
participants.
2.3 Integrative Look at Criminal Behavior
Today, many psychologists recognize that
criminal behavior is very complex. It results from a combination of risk
factors (which involve both biological and environmental factors) which
interact and aggravate one another. The more risk factors that are present, the
more likely one is going to engage in criminal behavior. There are several
theories that suggest a specific root of criminal behavior. These roots are
genetics, brain abnormalities and neurochemical imbalances.
Hutchings and Mednick (1975)
studied adoption cases and found that if both the biological and the adoptive
fathers had criminal records, then 36% of the sons also had a criminal record.
If the biological father was the only one who had a criminal record, it dropped
to 21% and if only the adoptive father had a criminal record, the rate of the
child also having a criminal record dropped to 11%. When neither fathers had criminal
records, the rate of sons having criminal records was 10%. This shows the importance
of environmental factors, combined with genetic factors that determine whether
or not one will hold a criminal record. A limitation to this experiment is the
fact that children are often placed with adoptive families who are similar to
their biological families. Some children were also placed into adoptive homes
long after their birth, which means the early-experiences the child had with
the biological parents could largely affect his/her behavior. It should be
noted here that "criminal behavior" refers to even the smallest of
crimes to the largest of crimes - from tax evasion to first degree murder. This
word is used in such a general sense that results of studies that use the word
"criminal behavior" could be inaccurate.
The brain is involved in emotion
making of a person, and thus can be attributed to one's behavior. Emotions are
controlled by the limbic system in the brain, and decision making takes place
in the frontal lobe. Therefore, if there is an impairment of the pathways
between the amygdala (which is responsible for emotional responses) and the
frontal lobe, the individual with the
impairment might have difficulty in moderating emotional reactions. This will
make social relationships difficult because the individual is not able to
develop empathy or feelings of guilt, and thus acts more capriciously, without
regard for the consequences.
Gender is also an interesting
aspect to crime. 90% of apprehended murderers were male, as well as 82% who
were arrested for violent crime. This is because of the low levels of serotonin
in men links to antisocial and impulsive behavior. The most important thing to
remember about biological factors and crime is that these factors are not the
only cause for criminal behavior. It is only when these factors are combined
with social and cognitive risk factors that violence and criminal behavior will
occur.
