Download Unit III: Biological Basis of Behavior

Unit III: Biological Basis of Behavior
Unit III Modules Module 9: Biological Psychology & Neurotransmission
Module 10: The Nervous & Endocrine Systems
Module 11: The Brain and Older Brain Structures
Module 12: The Cerebral Cortex
Module 13: Brain Hemispheres & Consciousness
Module 14: Behavior Genetics
Module 15: Human Nature
Module 9: Biological Psychology and Neurotransmission
Explain why psychologists are concerned with human biology.
9-1: Biology, Behavior, and Mind
Every thought, idea, mood, urge or action is based in biology – Biological Psychology (the scientific study of
the links between biological - genetic, neural, hormonal - and psychological processes) is a field dedicated
to the interplay between biology and psychology
Within roughly the past 100 years, biological psychologists have discovered that:
• the body is composed of cells
• nerve cells (neurons) comprise the nervous system – these cells conduct electricity and talk to one
another with chemicals (neurotransmitters)
• specific brain systems and structures serve specific functions
• information processed in these various systems and structures are integrated to construct one’s
experience of the real world (sight, sounds, meaning, memory, feelings, emotions, etc)
• the brain is adaptive and is wired and rewired through experience
Humans are biopsychosocial systems – the biopsychosocial approach is based on the belief that biological
(genetics, neurons), psychological (thoughts, emotions, beliefs) and social (cultural, environmental) factors all
work and interact together and are the basis of all human functioning
Module 9: Biological Psychology and Neurotransmission
Describe the parts of a neuron and explain how its impulses are generated.
9-2: Neurons
Neuron: a nerve cell – the basic building block of the nervous system
Module 9: Biological Psychology and Neurotransmission
Describe the parts of a neuron and explain how its impulses are generated.
9-2: Neurons
Anatomy of a Neuron
Cell Body – the cell’s life-support center
Dendrites – neuron’s extensions that receive
messages from other cells and conduct
impulses toward the cell body
Axon – neuron extension that sends messages
away from cell body to other neurons
Terminal Button (Branches) – form junctions
with other cells
Myelin Sheath – fatty tissue layer covering the
axon – enables impulses to travel faster
Neural Impulse (Action Potential) – electrical
impulse that travels from dendrites along
axon to terminal buttons *(up to 180 mph)
Module 9: Biological Psychology and Neurotransmission
Describe the parts of a neuron and explain how its impulses are generated.
9-2: Neurons
Action Potential – brief electrical impulse that travels down a
cell’s axon that results in a chemical release
1. Neuron stimulation causes a brief change in the electrical
charge of the neuron producing an action potential (from –
to +)
2. The action potential causes gates along the axon to open –
sodium ions rush in and potassium ions rush out – the
charge inside the axon segment changes from negative to
positive and then back to negative
3. Once the charge passes, the sodium ions are pumped out and
the potassium ions return
Action Potential https://www.youtube.com/watch?v=U0NpTdge3aw
https://www.youtube.com/watch?v=XdCrZm_JAp0
Module 9: Biological Psychology and Neurotransmission
Describe how neurons communicate.
9-3: Neurotransmission
Neurons do not touch – they are separated by a tiny
gap called the Synaptic Gap (Cleft) (the junction
between the axon tip of the sending neuron and the
dendrite of the receiving neuron)
Neurons use Neurotransmitters (chemical
messengers) to communicate – neurotransmitters
are released by the sending neuron and stimulate the
receiving neuron generating a new impulse – after a
neurotransmitter stimulates a receiving neuron, any
excess gets sucked back up by the sending neuron
(reuptake)
Neurotransmission https://www.youtube.com/watch?v=90cj4NX87Yk
https://www.youtube.com/watch?v=p5zFgT4aofA
Module 9: Biological Psychology and Neurotransmission
Describe how neurons influence behavior and how drugs affect neurotransmission.
9-4: Neurotransmitters and Behavior
Neurotransmitters (chemicals) are made in the brain and released by the neurons allowing them to “talk” – different neurotransmitters are released depending upon the neurons and their reason for talking. •
•
•
•
•
•
•
Acetylcholine (Ach): muscle action, learning & memory Dopamine: movement, learning, attention, emotion Serotonin: mood, hunger, sleep, arousal Norepinephrine: alertness, arousal, vigilance GABA (Gamma-Aminobutyric Acid): inhibits action potentials
Glutamate: enhances action potential, memory
Endorphins: pain reduction, pleasure
Alzheimer’s
Schizophrenia & Parkinson’s
Depression
Depressed Mood
Seizures, Tremors, & Insomnia
Migraines, Seizures
Module 9: Biological Psychology and Neurotransmission
Describe how neurons influence behavior and how drugs affect neurotransmission.
9-4: Neurotransmitters and Behavior
Drugs and other chemicals can disrupt
neurotransmission and / or affect the
brain’s natural transmitter production –
Agonist – bind to neurotransmitter
receptor sites and stimulate a
response (Morphine)
Antagonist – bind to neurotransmitter
receptor sites and block a response
(Anesthesia)
Neurotransmitter Pathways
Module 10: The Nervous and Endocrine Systems
Describe the functions of the nervous system and identify types of neurons.
10-1: The Nervous System
The Nervous System is the body’s electrochemical communication system, consisting of all the cells of the
central and peripheral nervous systems – enables humans to function
Central Nervous System (CNS): brain & spinal cord – body’s decision maker Peripheral Nervous System (PNS): links CNS with body’s sense receptors, muscles, and glands
Neurons allow information to travel through the Nervous System
Sensory (Afferent) Neurons: carry messages inward from body to the CNS for processing Motor (Efferent) Neurons: send instructions from the CNS out to the body’s muscles & glands
Interneurons: process information between sensory input and motor output
Module 10: The Nervous an Endocrine Systems
Describe the functions of the nervous system and identify types of neurons.
10-1: The Nervous System
Module 10: The Nervous an Endocrine Systems
Describe the functions of the nervous system and identify types of neurons.
10-1: The Nervous System
Motor & Sensory Neurons
Module 10: The Nervous and Endocrine Systems
Describe the functions of the nervous system and identify types of neurons.
10-1: The Nervous System
The Peripheral Nervous System (PNS) links CNS with body’s sense receptors, muscles, and glands – the PNS has two components:
Somatic Nervous System: transmits sensory input (ex touch, taste) to CNS and directs motor output - voluntary muscle movement
Autonomic Nervous System: influences muscles & glands of internal organs (heartbeat, digestion) – Autonomic Nervous System is self-regulating Sympathetic Nervous System: arouses – accelerates heartbeat, dilates pupils, releases adrenaline – mobilizes energy
Parasympathetic Nervous System: calms – decreases heartbeat, slows breathing – conserves
energy
Module 10: The Nervous an Endocrine Systems
Describe the functions of the nervous system and identify types of neurons.
10-1: The Nervous System – THE PNS
Module 10: The Nervous an Endocrine Systems
Describe the functions of the nervous system and identify types of neurons.
10-1: The Nervous System – THE CNS
The CNS made up of some 40 billion neurons comprising some 400 trillion synapses
The neurons of the brain create neural
pathways (clusters of neurons that talk regularly) - pathways are strengthened
through experience - everything we do (talking, walking, playing an instrument, throwing a ball) results from these pathways The spinal cord connects the brain and the
PNS enabling information from the body
to get to the brain and instructions from the brain to get to the body
Module 10: The Nervous and Endocrine Systems
Describe the functions of the endocrine system and
its interaction with the nervous system.
10-2: The Endocrine System
Endocrine System: the other communication system of body beside nervous system – uses chemicals (hormones) to communicate with body through the bloodstream – hormones influence sex drive,
hunger, & aggression and fear
The most influential gland in the Endocrine System is the
Pituitary Gland: located in the core of the brain – releases
hormones that regulate growth and influence other glands
Modules 11, 12, & 13: The Brain
The human brain keeps us primed to respond to the world around us. It is at the hub of a vast & complex
communications network that constantly seeks & collects information from the rest of the body & the outside
world. As the brain interprets this information, it generates experience – sights, sounds, emotions, thoughts,
etc. The primary task of the brain is to help maintain the whole body in an optimal state relative to the
environment, in order to maximize the chances of survival. The brain accomplishes this by registering stimuli
& then responding by generating actions.
Key Features of the Brain:
• Processing - The brain registers a vast amount of information; however, only a small amount is
actually selected for processing
• Sending Signals - Cells in the brain send signals to one another enabling us to detect & respond to
environmental stimuli
• Modules & Connections - The brain is modular – different parts do different things. These parts;
however, are densely interconnected. Thus, many parts only work w/
the support of other parts.
• Individuality – All brains share basic anatomy, but each individual brain is unique based on genetics
and experience. All brains are visibly different in how they function.
• Plasticity - Brains are physically changed through experience enabling people to better respond to the
demands of the environment.
Modules 11, 12, & 13: The Brain
Brain Facts:
Weight - 3 lbs. (roughly the size of a grapefruit)
Color - pinkish-gray
Comprised of some 100 billion nerve cells (neurons)
The human brain is the most complex structure known - it regulates all body functions, controls behavior,
generates emotions, desires, motives, & insights, processes experiences, and even possesses the ability to
think about itself
The brain is a developing system - although total brain weight doesn’t change after age 5 - the brain does go
through a transformation: white matter (responsible for information transmission) increases and gray
matter (responsible for information processing) decreases in the cerebral cortex as humans age - believed to
increase overall brain efficiency
Research shows that certain structures of the adult brain (cerebral cortex & hippocampus) can generate new
neurons (neurogenesis) - by the time one turns 70, the typical human brain possesses roughly 98% of its
nerve cell supply
Research has proven that interaction is vital to brain development - studies show infants raised in isolation or
with limited contact are adversely affected in their cognitive, social, and physical development
Ode to the Brain https://www.youtube.com/watch?v=JB7jSFeVz1U
Modules 11, 12, & 13: The Brain
The 3 Human Brains
Brain
Location
Animals
Function
“Archaic Brain”
The Brain
Stem
Reptiles
Instinctual Behavior (keeping us safe)
Life Sustaining Functions (breathing & heartbeat)
The Limbic
System
Cats, Dogs
(all mammals)
Mood, Memory, & Hormone production
Cognitive & Attention processing
The Cortex
Humans
Most Complex Structure in the Universe
“Old Brain” “New Brain”
Higher Cognition, Abstract Thought, Formation &
Comprehension of Language, Social Behavior, Tool
Usage
Modules 11, 12, & 13: The Brain How the Human Brain Works - https://www.youtube.com/watch?v=9UukcdU258A
Module 11: Studying the Brain and older Brain Structures
Describe techniques for studying the brain’s connections to behavior & mind.
11-1: The Tools of Discovery
The mind is what the brain does – the systems, structures and chemicals of the brain create experience
Throughout history, brain injuries have provided insights into the functions of specific brain areas –
• damage to one side of the brain creates numbness or paralysis on the other side of the body
• damage to the back of the brain creates disrupted vision
• damage to the left-front of the brain impairs speech difficulties
New technologies are enabling neuroscientists to access the brain in new ways providing remarkable insight • lesioning: destruction of brain tissue – helps to provide insight into brain function
• stimulation: using electrical, chemical, magnetic activity to facilitate brain function
• Electroencephalogram (EEG): amplified recording of brain’s electrical activity
• Computed Tomography (CT): x-ray photograph of the brain – can show damaged brain areas
• Positron Emission Tomography (PET): image of brain activity that captures glucose consumption
• Magnetic Resonance Imaging (MRI): image of brain molecular activity that captures brain anatomy
• Functional MRI (fMRI): brain image that captures brain function and structure
Brain research is providing a better understand of the brain and is opening the door to endless possibilities –
Brain-Computer Interface technology & Cognitive Neural Prosthetics (106-107) allow people &
animals to control robotic & artificial limbs through thought
Module 11: Studying the Brain and older Brain Structures
Describe techniques for studying the brain’s connections to behavior & mind.
11-1: The Tools of Discovery
EEG
MRI
CT (CAT)
PET
fMRI
Module 11: Studying the Brain and older Brain Structures
Describe the components of the brainstem and summarize the
functions of the brainstem, thalamus & cerebellum.
11-2: Older Brain Structures
Brainstem - lowest part of brain - performs functions that keep body working properly (Archaic Brain)
Medulla: where spinal cord enters skull – controls breathing, blood pressure & heart rate – crossover point where nerves to & from each side of brain connect w/ other side of body
Pons: regulates sleep and dream cycle & plays a role in coordinated movement
Thalamus: brain’s sensory control center - routes sensory input to parts of brain that deal with the senses of sight, sound, taste, touch
Reticular Formation: sets of neurons extending from spinal cord to thalamus – influences arousal & wakefulness – monitors incoming sensory information & directs attention to important things
Cerebellum: to rear of brainstem – comprised of 2 hemispheres – cerebellum coordinates
movement, balance, posture, & motor function
Module 11: Studying the Brain and older Brain Structures
Describe the components of the brainstem and summarize the
functions of the brainstem, thalamus & cerebellum.
11-2: Older Brain Structures – The Brain Stem
Module 11: Studying the Brain and older Brain Structures
Describe the limbic system’s structures and functions.
11-3: The Limbic System
Forebrain - part of brain filling much of the skull – involved w/ emotions and memory (Old Brain)
Limbic System - neural system that controls emotions & drives
Amygdala - neural clusters that influence emotion (aggression & fear)
Hippocampus – processing memories & plays in learning: transfers new information to
memory – also involved in spatial awareness
Hypothalamus – links nervous system w/ endocrine system – governs the the endocrine system via the pituitary gland – performs maintenance duties: regulating hunger, thirst, body temp – also influences pleasure
The Limbic System is the brain’s reward & pleasure center – dopamine is the brain’s feel good chemical
• nucleus accumbens: brain structure to front of hypothalamus involved in pleasure & motivation – modulates dopamine
Module 11: Studying the Brain and older Brain Structures
Describe the limbic system’s structures and functions.
11-3: The Limbic System
Module 12: The Cerebral Cortex
Identify the various regions and functions of the cerebral cortex.
12-1: The Cerebral Cortex
Cortex – surface of the brain – higher functions (New Brain)
Cerebral Cortex - surface of the brain - neural cells that cover the cerebral hemisphere – controls conscious
experience, thinking, speaking, & intelligence – cerebral cortex is comprised of some 20 billion nerve cells that form some 300 trillion synaptic connections – the neurons of the cortex are protected by glial cells
Lobes of Cerebral Cortex:
Frontal Lobe: language expression, judgment & planning, personality, movement – prefrontal cortex is responsible for allocating the brain’s 13 watts
Motor Cortex: controls voluntary movement
Parietal Lobe: specializes in sensation - taste, touch, hearing, & body position
(Somato)Sensory Cortex: processes sensations of touch: temp, pain & pressure Occipital Lobe (Visual Cortex): visual processing
Temporal Lobe (Auditory Cortex): hearing & long-term memory storage
Association Cortex: areas of cortex not involved in motor or sensory functions – association areas play a role in higher mental functioning like thinking, remembering, learning, speaking
Module 12: The Cerebral Cortex
Identify the various regions and functions of the cerebral cortex.
12-1: The Cerebral Cortex
Cortex – surface of the brain – higher functions (New Brain)
Language – language requires coordination of many brain areas (speaking, reading, writing, comprehension)
Broca’s Area: controls speech muscles (frontal lobe)
* light blue
Wernicke’s Area: controls comprehension (temporal lobe)
* green Angular Gyrus: recodes visual input (parietal lobe)
*orange
Module 12: The Cerebral Cortex
Identify the various regions and functions of the cerebral cortex.
12-1: The Cerebral Cortex
Module 12: The Cerebral Cortex
Identify the various regions and functions of the cerebral cortex.
12-1: The Cerebral Cortex
Angular
Gyrus
Module 12: The Cerebral Cortex
Identify the various regions and functions of the cerebral cortex.
12-1: The Cerebral Cortex
Module 12: The Cerebral Cortex
Identify the various regions and functions of the cerebral cortex.
12-1: The Cerebral Cortex – The Motor Cortex & Sensory Cortex
Module 12: The Cerebral Cortex
Identify the various regions and functions of the cerebral cortex.
12-1: The Cerebral Cortex – Phineas Gage
Phineas Gage https://www.youtube.com/watch?v=9QXI_BxlY7M
Module 12: The Cerebral Cortex
Discuss the brain’s ability to reorganize itself, and define neurogenesis.
12-2: Brain Plasticity
The brain is limited because –
many of the brain’s neurons typically do not regenerate
some brain areas are preassigned to specific functions
However, the brain is constantly changing and building new pathways through experience & the brain
(particularly the young brain) has the ability to reorganize neural tissue in response to damage – the
brain possesses PLASTICITY: the brain’s ability to change by building new pathways as a result of
experience or by reorganizing after damage
Some brain structures & areas are capable of Neurogenesis: the formation of new neurons
Brain Plasticity –
https://www.youtube.com/watch?v=8Vo-rcVMgbI
https://www.youtube.com/watch?v=VaDlLD97CLM
http://www.today.com/id/36032653/ns/today-today_health/t/meet-girl-half-brain/
Module 13: Brain Hemisphere Organization and
the Biology of Consciousness
Explain how split-brain research helps us understand
the functions of the two brain hemispheres.
13-1: The Divided Brain
The brain is comprised of 2 hemispheres each serving differing functions (lateralization) – the hemispheres
are connected by the Corpus Callosum: bundle of neural fibers that connect right & left brain hemispheres
– enables the hemispheres to communicate w/ one another - split brain research has allowed psychologists
to better understand lateralization – Roger Sperry and Michael Gazzaniga are pioneers in split brain research
Split Brain Research
https://www.youtube.com/watch?v=lfGwsAdS9Dc
https://www.youtube.com/watch?v=roKV8XJHXKc
Module 13: Brain Hemisphere Organization and
the Biology of Consciousness
Explain how split-brain research
helps us understand the functions
of the two brain hemispheres.
13-1: The Divided Brain
Right Hemisphere: creative, emotion hemisphere – sees wholes
functions: regulates negative emotions, memory for shapes & music, visual images, facial recognition, excels in inferring, plays a role in self awareness, & perceptual problems: pattern recognition & spatial relationships
Left Hemisphere: logical, analytical hemisphere – sees parts / pieces of the whole
functions: regulates positive emotions, speech & language, movement sequence control, memory for words & numbers, language, analysis, creating explanations
Right hemisphere controls the left side of the body & the left hemisphere controls the right side of the body.
Additionally, sensory input experienced on the right side of the body is processed in the left
hemisphere and sensory input experienced on the left side of the body is processed in the right
hemisphere
Module 13: Brain Hemisphere Organization and
the Biology of Consciousness
Explain what is meant by dual processing.
13-2: The Biology of Consciousness
“The mind is what the brain does.” - Marvin Minsky
How do brain cells talking create the physical experience of eating pizza, or the color blue, or the idea of infinity, or the feeling of happiness? - In other words, how do talking brain cells create the reality
we experience?
Consciousness is perhaps the most elusive concept in psychology – Consciousness: our awareness of
ourselves and our environment – but this is only an aspect of all consciousness encompasses, and
consciousness continues to be one of the least understood psychological concepts – the question
neuroscientists are trying to answer is: How does the brain create consciousness? Consciousness is a critical function of the cerebral cortex – Cognitive Neuroscience (the study of the brain activity linked with mental processes: perceiving, thinking, remembering, & using language): is exploring connections between specific brain function & conscious experience Module 13: Brain Hemisphere Organization and
the Biology of Consciousness
Explain what is meant by dual processing.
13-2: The Biology of Consciousness
Dual Processing: information is simultaneously processed both consciously and unconsciously – much of
the work the brain does occurs outside of awareness (unconsciously) – 1 study showed that activity
in the brain preceded people’s conscious decision-making – the research team, simply by looking at
brain scans, was able to predict w/ 60% accuracy and up to 7 seconds beforehand which hand test
subjects would opt to push a button with
The purpose of the nonconscious mind is to free up consciousness – the conscious mind works sequentially,
it is slow and has limited capacity (we can only focus on so much at 1 time) – unconscious
processing is fast and capable of dealing with multiple streams of information simultaneously – the
nonconscious mind serves the purpose of allowing the conscious mind to be ready to process things
that are important and require attention – if we lacked the capacity of dual processing, we would
become overwhelmed by all of the external and internal stimulation we experience
Module 14: Behavior Genetics
Define genes and describe how behavior geneticists explain individual differences.
14-1: Genes
Humans share a biological heritage & behavioral tendencies – humans’ shared brain architecture predisposes
them to sense the world, develop language, and feel hunger through identical mechanisms – humans
share many personal and social behaviors – how do we explain how and why people are the way
they are? - behavioral sciences explore how nature and nurture work together to define who we are
“Nature is all that man brings with himself into the world; nurture is every influence that affects him after his birth” – Francis Galton
Behavior Geneticists: study the power & limits of genetic / hereditary (internal) and environmental (external)
influences on behavior – the human body contains 46 Chromosomes: threadlike structures made up
of DNA: inherited genetic material (human DNA is 99.9% the same, human & chimps share 96% of
the DNA sequence) – 23 chromosomes come from dad & 23 from mom – humans possess roughly
22,500 Genes: units of heredity (DNA segments) – humans è cells è chromosomes è DNA è genes
Genes are either active or inactive – environmental factors make genes activate or inactive – many traits are
influenced by genes: height, hair & eye color, intelligence, temperament Temperament, Heredity, & Genes
https://www.khanacademy.org/test-prep/mcat/behavior/behavior-and-genetics/v/temperment-heredity-genes
Module 14: Behavior Genetics
Define genes and describe how behavior geneticists explain individual differences.
14-1: Genes
Twin and Adoption studies provide an opportunity for behavioral scientist to explore the role of heredity and
the environment – identical twins develop from a single fertilized egg (genetically identical),
whereas fraternal twins develop from separate eggs (genetically no more similar than ordinary
siblings) - twin and adoption studies provide two groups for behavioral scientists to study: genetic
relatives (biologically related) & environmental relatives (not biologically related)
Research on twins and adoptees shows that:
• identical twins tend to be behaviorally more alike than fraternal twins • separated twins, whether identical or fraternal, tend to have somewhat less identical personalities • adopted children tend to be more like biological parents than adoptive parents in regards to extraversion & agreeableness • the personalities of children reared together, whether related or not, are only modestly influenced by the environment - in terms of personality, genetics are more important than the environment
• one’s environment (parents) does influence attitudes, values, manners, faith, and political views The Jim Twins https://www.youtube.com/watch?v=qw3S35wGgT8
Module 14: Behavior Genetics
The promise of molecular genetics.
14-2: Molecular Genetics
Molecular Genetics: the study of the molecular structure and function of genes seeks to identify the specific
genes that influence traits & behavior – genetic testing is opening the door to disease & disorder
treatment – what are the implications of such testing both positive and negative?
Genetic Testing
https://www.youtube.com/watch?v=EpzwoVv3BWc
https://www.youtube.com/watch?v=ICdWvlZFkdE
Module 14: Behavior Genetics
What is meant by heritability, and how does it relate to individuals and groups?
14-3: Heritability
Heritability: extent to which variation among individuals is attributed to their genes – heritability helps to
provide insight into the influence of genes and the environment – if environmental conditions
among a group of people are similar then heritability would primarily account for any behavioral
differences – however, if there are significant differences in the environment then we would expect
to see more diversity in behavior (heritability would be significantly less of a factor in behavioral
differences)
Heritability of IQ is said to be 75%, meaning IQ is primarily determined by genetics with some
environmental influence
Heritability
https://www.khanacademy.org/test-prep/mcat/behavior/behavior-and-genetics/v/heritability
Module 14: Behavior Genetics
How do heredity and environment work together.
14-4: Gene – Environment Interaction
The most important behavioral feature of humans is their capacity to adapt - humans have a critical biological
mechanism: adaptation – it is both genetically and environmentally influenced
Genes and environment work together; they interact – genes self-regulate, they are triggered by
environmental factors – behavioral scientists have moved beyond a nature versus nurture debate and
embrace nature through nurture – Epigenetics: the study of environmental influences on genetic
expression is a discipline dedicated to studying how the environment influences genes
Studies show that environmental factors like diet, drugs, & stress affect gene expression – infant rats deprived
of their mother’s normal licking had less capacity to respond to stress (because of the deprivation,
their stress response genes didn’t kick on) – the key to Epigenetics is understanding the imprint the
environment leaves of the brain
Genes & the Environment
https://www.khanacademy.org/test-prep/mcat/behavior/behavior-and-genetics/v/gene-environment-interaction Module 15: Evolutionary Psychology
Describe evolutionary psychologists use of natural selection to explain behavior.
15-1: Natural Selection and Adaptation
Evolutionary Psychologists study the evolution of behavior – the traits humans share today have been shaped
by Natural Selection: the process of the most critical trait variations (those that most contribute to
survival) being passed down to succeeding generations over the course of human evolution –
human behavioral & biological similarities are a product of our shared Genome (genetic makeup) –
humans are 99.9% the same genetically and no more than 5% of differences between people arise
from population group differences – 95% of human variation exists within a specific group
population – this shared human genome is a product of evolution – the genes that have most
enhanced human survival have been those that have been passed along Module 15: Evolutionary Psychology
Gender differences in sexuality and mating.
15-2 & 15-3: Human Sexuality – The Evolutionary Perspective and Criticisms
According to evolutionary psychologists, humans are predisposed to act in ways that ensure human survival – nature selects behaviors that increase the likelihood that our species will survive – behaviorally men and
women are more alike than different, but clearly there are specific differences between the sexes – man’s
more casual and recreational attitude on sex is thought to serve an evolutionary purpose – women ensure the species survival by pairing wisely & men by pairing widely
Research shows:
men prefer women w/ waists roughly 1/3 the size of the hips (sign of fertility) and that boys & men, regardless of culture or age, are more attracted to women in peak fertility years (mid 20’s)
women prefer men that are mature, dominant, bold, and affluent – more potential for long-term mating & investment in offspring Critics of such the evolutionary approach argue that:
genetic determinism undermines efforts to create a more egalitarian society
such explanations detract from the influence of society & culture on gender roles Module 15: Evolutionary Psychology
Describe the biopsychosocial approach to individual development.
15-4: Reflections on Nature & Nurture
Humans are a product of the complex interplay between genes and experiences, but they are also an open system – genetics may drive us to procreate, but we can choose to be celibate – our decisions shape our environments - Biopsychosocial Approach Everything psychological is simultaneously biological – thinking, feeling, and acting are a product of brain activity – the brain creates the mind, and the mind influences the brain