Transcript Assumption 1 - Social Sciences @ Groby

Biological approach - assumptions
What is the biological approach?
The biological approach combines psychology and biology
to provide physiological explanations for human
behaviour.
Biological psychology tries to explain how we think, feel
and behave in terms of physical factors within the body.
Assumptions of the biological approach
1. Evolutionary influences
2. Localisation of Brain function
3. Neurotransmitters
 These three things all have an effect on our personality and
psychology
 Challenge: What do you already know about these three things?
Assumption 1: Evolutionary Influences
 What do you know about evolution?
 When have you come across it before?
 Do you think human behaviour has evolved?
 How would we know?
 Evolution is the change of a species over time
 Charles Darwin
Assumption 1: Evolutionary Influences
 Darwin’s theory of natural selection is based on three main
assumptions.
1. Only a small proportion of each generation survives to
reproduce.
2. Offspring are not identical to their parents, and so each
generation has a degree of variation, and that at least some of
this variation is heritable (can be passed on through genes).
3. Some characteristics give the animal an advantage over others
in the ability to survive and reproduce.
 Characteristics which give the animal a greater chance of survival
and reproduction are adaptive.This is natural selection. If a
characteristic has survived and been passed down through the
generations, it must have been adaptive and have given the animal
a survival advantage.
Assumption 1: Evolutionary Influences
Natural selection
 Altruistic behaviour is an
example of this – parents risk
their lives to save the life of
their offspring. Natural
selection suggests that
altruism is an inherited and
adaptive trait because saving
the life of offspring enhances
the gene pool.
Assumption 1: Evolutionary Influences
 How could evolution explain a possible
biological predisposition to fear snakes and
spiders?
Assumption 1: Evolutionary Influences
 In practically every culture in
the world, men prefer young
rather than old women,
women with wide hips and
narrow waists, and women
with full lips and large eyes.
 What could be the
evolutionary explanation for
this?
Assumption 1: Evolutionary Influences
 Full lips and large eyes
are signs of youth.
Younger women are
more fertile. Men who
have sex with young
women are more likely
to produce offspring.
 Narrow waists and wide
hips are also signs of
fertility and health.
Assumption 1: Evolutionary Influences
 Can you think of any other human behaviours
that we could argue are “adaptive”?
Aggression?
Intelligence?
Love?
Assumption 1: Evolutionary Influences
Environment of evolutionary adaptiveness" (EEA).
 To understand the functions of the brain, we must
understand the environment in which the brain
evolved.
 Humans began evolving around 2 million years
to around 100,000 years ago.
 Evolutionary psychologists argue that humans
are adapted to the environment that our
ancestors would have faced.
Assumption 1: Evolutionary Influences
Those able to
form alliances
would survive in
a complex social
world
Large brain
size in
comparison
to body
 Look at the image above of what we believe life was life for our
ancestors.What behaviour and traits would have been adaptive for
early humans? Do we still have these traits today?
Assumption 3: Neurotransmitters
 Neurons are the cells which are found in the brain and
nervous system.
 They work by sending chemical and electrical messages
to each other.
Neurotransmitters
Assumption 3: Neurotransmitters
 The whole of the nervous system (including the brain) is composed
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of interconnected neurons.
These are long thin cells that convey messages from one place to
another. They can be smaller than 1mm, or longer than a metre!
The brain contains billions of these neurons.
Neurons pass messages from one neuron to the next via small gaps
between the neurons called a synapse (20 mm wide).
These messages are passed from neuron to neuron by chemicals
called neurotransmitters, released from presynaptic vesicles.
Neurotransmitters are chemical messengers that act between
neurons within the brain. This allows the brain to process thoughts
and memories.
 Different
neurotransmitters have
different effects on us.
 http://imgur.com/xDQ
B5fC
Assumption 2: localisation of brain function
 The two halves of the brain are called
____________
hemispheres
billion neurons
 There are roughly 100
________
in the brain and spinal cord.
 Behaviour can be explained in terms of
different areas of the brain. Many
different areas of the brain have certain
functions. The cerebral cortex covers
the surface of the brain (a bit like a tea
cosy!) and is folded and grey in colour –
this region is responsible for higher
cognitive functions.
Assumption 2: localisation of brain function
 The cerebral cortex is divided into four areas. The
most important is the frontal lobes deal with
thinking and creativity.
 The parietal lobe receives sensory information such
as temperature, touch and pain.
 The temporal lobes are responsible for memory
processing, as well as processing auditory information.
 The final lobe is the occipital lobe which deals with
vision and receives information directly from the eyes.
Assumption 2: localisation of brain function
 There are specific areas of the brain linked to the processing of
language.
 In the middle of the 19th century, French neurosurgeon Paul Broca
studied eight patients with language problems. He examined their brains
after death and found that they had damage to a specific area of their left
hemispheres. This area has been named ‘Broca’s area’; it is associated
with speech production and found in the posterior portion of the frontal
lobe.
 Carl Wernicke, a German neurologist, discovered another area of the
brain that was involved in understanding language. This area, named
‘Wernicke’s area’, is in the posterior portion of the left temporal lobe.
His patients could speak but were unable to understand language.
Assumption 2: localisation of brain function
 EXTRA: Remember the case of Phineas Gage? What
happened to him? How does this link to brain localisation?
 Some interesting brain
facts!
Key Terms “You Say We Pay”
The
Biological
Neuron
Oxytocin
Receptor
Seratonin
Lobe
Adaptive
Synapse
Neurotransmitter
Broca’s
Dopamine
Dendrite
Area
Wenicke’s
Area
Natural
Selection
Approach
Explaining relationships
 Without looking at the book, how could the biological approach
apply to human relationships?
 Romantic relationships
 Sibling relationships
 Parent/child relationships
 Pet/Owner relationships
 Read the box on page 11. What do you think?
 We will come back to this question again once we have done all 5
approaches.
Explaining relationships
 Evolutionary theory
 Relationships form with individuals who possess certain traits – the
traits that enhance reproduction are naturally selected. Males and
females have different selective pressures.
 Males look for:
 Fertility (young)
 Health (smooth skin, red lips, narrow waist)
 Females look for:
 Fertility and health
 Resources (food and shelter)
 Parental investment theory (Trivers, 1972) suggests that as female
investment is so high they must be choosier when it comes to a partner.
This explains why younger women often go for an older male.
Explaining relationships
 Neurotransmitters
 Dopamine is pleasure seeking and reward-driven behaviour. So finding a
relationship will give a hit of this.
 Oxytocin is linked with human bonding, trust and loyalty. High levels of
oxytocin are linked to romantic attachment – a lack of physical contact
will reduce oxytocin, leading to feelings of longing.
Explaining relationships (sibling)
 Kin selection – traits that enhance the chance of survival of those
with similar genes. Natural incentive to help our siblings survive.
This is through time, energy and resources to promote health.
Application Task
Balloon
1.
Label the four lobes of the brain.
 frontal lobes deal with thinking and creativity.
 parietal lobes receives sensory information such as
temperature, touch and pain.
 temporal lobes are responsible for memory processing,
as well as processing auditory information.
 occipital lobe deals with vision and receives information
directly from the eyes.
Label Wernicke’s and Broca’s areas.
3. Find out which areas of the brain are affected by
2.
 Addiction
 Depression
 Criminal behaviour
 Love
 Challenge: Use the 3D
brain app to find
another area of the
brain and it’s
responsibility.
Answers
 Addiction = limbic system
 Depression = amygdala
 Criminal behaviour = amygdala
 Love = striatum
Homework
 Create a flashcard on the assumptions of the
biological approach.
 Use the SEE format:
 State the assumption
 Explain and elaborate, and give an
 Example in Psychology
 You’ll have a quick test next lesson!