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Behavior Genetics
Chapter 3 (pg.95-105)
Question: How much effect does genetics have on behavior?
Behavior Genetics
To study our differences and weigh the relative effects of heredity and environment.
Genes: Our Codes for Life
 Every cell nucleus in the body contains the genetic master code for the entire body.
 If related to a book:
Chapters: The chromosomes are each composed of a coiled chain of the molecule…
Book: DNA, which is a complex molecule containing the information that make up the chromosomes.
Words: Genes are small segments of the giant DNA molecules
 Variations in DNA define each person’s uniqueness.
 Gene complexes influence human traits.
Twin Studies
 To study the influence of environment and heredity it is easy to experiment with identical and fraternal twins.
 Identical twins develop from one egg and are genetically identical.
 Fraternal twins develop from separate fertilized eggs.
 After numerous studies, it seems that genes do influence traits such as emotional instability and social
effects such as divorce.
 Some believe that even though separated at birth, many identical twins tend to have similar personalities.
 After watching hundreds of adopted families studies have shown that adoptee traits bear more similarities to their
biological parents than adoptive parents.
Temperament Studies
It seems that our biologically rooted temperament helps form our enduring personality. (Exp. The most emotionally
intense preschoolers tend to be relatively intense as young adults.)
Heritability
The proportion of variation among individuals that we can attribute to genes.
 Analogy: “Genes and environment – nature and nurture – work together like two hands clapping. Genes not only
code for particular proteins, they also respond to environments.”
Gene – Environment Interaction
 Environment triggers gene activity.
 Our genes affect how people react to and influence us.
Molecular Genetics
 The goal of molecular behavior genetics is to find genes that influence normal human traits (ex. body weight)
 With this, in the future, parents might know the traits of their children before they are born.
Perceptual Interpretation
Chapter 6 (pg.254-261)
Question: To what extent do we learn to perceive?
Sensory Deprivation and restored vision
 We perceive and recognize faces as a whole, but those who are deprived of sight during infancy surpass the rest
when it comes to recognizing features.
Perceptual Adaptation
The ability to adjust to an artificially displaced or even inverted visual field.
Perceptual Set
 Our perceptual set or mental predisposition influences what we perceive.
 It is hard to see the truth once we have formed a wrong idea of reality.
 From our experiences, we form concepts to interpret new information.
 A given stimulus may trigger radically different perceptions. Party because of our differing schemas, but also
because of the immediate context.

“The river of perception is fed by two streams: sensation and cognation.”
Prologue: Contemporary pg 8-15
Nature-nurture issue: the longstanding controversy over the relative contributions that genes and experience make to the
development of psychological traits and behaviors.
natural selection: the principle that, among the range of inherited trait variations, those that lead to increased reproduction
and survival will most likely be passed on to succeeding generations.
Levels of analysis: the differing complementary views, from biological to psychological to social-cultural, for analyzing any
given phenomenon.
Biopsychosocial approach: an integrated perspective that incorporates biological, psychological, and social-cultural levels
of analysis.
Applied research: scientific study that aims to solve practical problems.
Counseling psychology: a branch of psychology that assists people with problems in living (often related to school, work,
or marriage) and in achieving greater well-being.
Clinical psychology: a branch of psychology that studies, assesses, and treats people with psychological disorders.
Psychiatry: a branch of medicine dealing with psychological disorders; practiced by physicians who sometimes provide
medical (for example, drug) treatments as well as psychological therapy.
Neuroscience: How the body and brain enable emotions, memories, and sensory experiences
-How are messages transmitted within the body? How is blood chemistry linked with moods and motives?
Evolutionary: How the natural selection of traits promotes the perpetuation of one's genes
-How does evolution influence behavior tendencies?
Behavior genetics: How much our genes and our environment influence our individual differences
-To what extent are psychological traits such as intelligence, personality, sexual orientation, and vulnerability to depression
attributable to our genes? To our environment?
Psychodynamic: How behavior springs from unconscious drives and conflicts
-How can someone's personality traits and disorders be explained in terms of sexual and aggressive drives or as the
disguised effects of unfulfilled wishes and childhood traumas?
Behavioral: How we learn observable responses
-How do we learn to fear particular objects or situations? What is the most effective way to alter our behavior, say, to lose
weight or stop smoking?
Cognitive: How we encode, process, store, and retrieve information
-How do we use information in remembering? Reasoning? Solving problems?
Social-cultural: How behavior and thinking vary across situations and cultures
-How are we—as Africans, Asians, Australians, or North Americans—alike as members of one human family? As products
of different environmental contexts, how do we differ?
Ch. 3 Evolutionary pg 107-112
“Women pair wisely. Men pair widely”
Evolutionary Psychology: the study of the evolution of behavior and the mind, using principles of natural selection.
Evolutionary School of Thought: How the natural selection of traits promotes the perpetuation of one's genes -How does
evolution influence behavior tendencies?
Nature-nurture issue: the longstanding controversy over the relative contributions that genes and experience make to the
development of psychological traits and behaviors.
Natural selection: the principle that, among the range of inherited trait variations, those that lead to increased reproduction
and survival will most likely be passed on to succeeding generations.
Gender: in psychology, the biologically and socially influenced characteristics by which people define male and female.
Gender role: a set of expected behaviors for males and for females.
Gender-typing: the acquisition of a traditional masculine or feminine role.
Gender identity: one’s sense of being male or female. (Some claim to be born in the wrong body because they can’t
identify their gender to match their genitalia)
Socialization has become a means of manipulation, making actions “socially acceptable”
-“Moreover, if socialized to value lifelong commitment, men may sexually bond with one partner; if socialized to accept
casual sex, women may willingly have sex with many partners.” Pg 112
People impact each other as much as the environment
Parents: discipline, education, responsibility, orderliness, charitableness, interaction with authority
Peers: Learning cooperation, lead to popularity, inventing individual style, interaction with people of same age and/or
interest
A basic understood concept in evolutionary psychological studies, men search to mate with many partners to satisfy their
unconscious drive to reproduce as many off spring as possible. Men look for women with “baby bearing” capabilities for this
reason
Women look to mate with masculine male figures for dominance and support. Also, to guarantee their offspring a better
chance for survival.
Men of the ages 16-24 tend to feel immortal and are more likely to do extreme activities to attract a female mate
The pre-existing expectation of gender role may be restricting progress and evolution in society, especially for the ideal
house wife woman.
Correlation
Correlation is a statistical measure of how one factor (usually a behavior or trait), varies to another factor. There can be
positive, negative, or no correlation, usually derived from scatterplots or the correlation coefficient which ranges from -1 to 1.
CORRELATION DOES NOT MEAN CAUSATION. A nearly irresistible thinking error is assuming that correlation proves
causation. But no matter how strong the relationship, it does not! Correlation can help us predict events more accurately
going with the more likely outcome, but it only indicates the possibility of a cause-effect relationship. It does not prove
causation.
An illusory correlation is the perception of a relationship where none exists. Illusory correlations occur when we over-rely on
confirming evidence and ignore disconfirming evidence and evidence confirming the opposite. When we believe there is a
relationship between two things, we are likely to notice and recall instances that confirm our belief. When we notice random
coincidences, we may forget that they are random and instead see them as correlated. Thus, we can easily deceive
ourselves by seeing what is not there.
Perceptual Illusions
Perceptual illusions are created from the ways we organize and interpret our sensations. The brain's rules for constructing
perceptions explain some of the puzzling illusions we've considered. We constantly filter sensory information and infer
perceptions in ways that make sense to us.
When given a cluster of sensations, we tend to organize them into a gestalt, or an organized whole.
When vision competes with other senses, vision usually wins—a phenomenon called visual capture. In most
cases, vision captures the other senses, and we naturally associate them with vision. For example, if the sound of a movie
comes from a projector behind us, we perceive it as coming from the screen, where we see the actors talking.
Chapter Eight
Learning
“No topic is closer to the heart of psychology than learning.”
How Do We Learn?
Learning – a relatively permanent change in an organism's behavior due to experience
Associative Learning – learning that certain events occur together
Ivan Pavlov
After studying salivary secretion in dogs, he noticed that when he worked with the same dog repeatedly, it began salivating to stimuli
associated with food.
Classical Conditioning – learning in which an organism comes to associate stimuli
Unconditioned Stimulus (UCS) – any stimulus that causes a natural reaction
Unconditioned Response (UCR) – an organism’s natural response to a stimulus
Conditioned Stimulus (CS) – any stimulus paired with UCS (unnatural)
Conditioned Response (CR) – always the same as UCR
Respondent Behavior – behavior that occurs as an automatic response to some stimulus
Five Major Conditioning Processes
Acquisition – associating a neutral stimulus with an unconditioned stimulus
Extinction – the diminishing of a conditioned response
Spontaneous Recovery – reappearance, after a pause, of an extinguished conditioned response
Generalization – the tendency for stimuli similar to the CS to elicit similar responses
Discrimination – ability to distinguish between a CS and stimuli that don’t signal an UCS
Operant Conditioning
Operant Conditioning – a type of learning in which behavior is strengthened if followed by a reinforcer or diminished if followed
by a punisher.
Operant Behavior – behavior that operates on the environment, producing consequences
Positive Reinforcement → add a desirable stimulus
Negative Reinforcement → remove an averse stimulus
zPositive Punishment → administer an averse stimulus
Negative Punishment → withdraw a desirable stimulus
Chapter Two
Neuroscience and Behavior
“Everything psychological is simultaneously biological.”
Neuron Structure
Our body's neural information system is complexity built from simplicity. Its building blocks are neurons, or nerve cells.
Dendrite – tree-like extensions, receive messages
Cell Body – the cell’s nucleus
Axon – extension of a neuron, through which messages pass
Myelin Sheath – fatty layer of tissue, encases the axon and controls speed of message
Terminal Branches – form junctions with other cells
Synapse – empty space between axon tip of sending neuron & dendrite of receiving neuron
Information → Dendrite → Cell Body → Axon → Other neurons, muscles, or glands
Neuron Communication
A neuron fires an impulse when it receives signals from sense receptors stimulated by pressure, heat,
stimulated by chemical messages from neighboring neurons.
Action Potential – neural impulse; brief electrical charge that travels down an axon
Threshold – level of stimulation required to trigger a neural impulse
or light, or when it is
Neurotransmitters
When the action potential reaches the knoblike terminals at an axon's end, it triggers the release of chemical messengers, called
neurotransmitters.
Neurotransmitter
Function
Malfunctions
Acetylcholine (ACh)
Enables muscle action, learning, and memory.
Deteriorates with Alzheimer's
disease
Dopamine
Influences movement, learning, attention, and
Excess → Schizophrenia
emotion.
Decrease → Parkinson’s
Serotonin
Affects mood, hunger, sleep, and arousal.
Depression
Norepinephrine
Helps control alertness and arousal.
Depression
GABA
A major inhibitory neurotransmitter.
Glutamate
A major excitatory neurotransmitter; involved in
memory.
Undersupply linked to seizures,
tremors, and insomnia.
Too much → migraines or seizures
The Nervous System
Neurons are the elementary components of our nervous system, our body's speedy electrochemical information network.
Nerves – neural "cables" containing many axons
Sensory Neurons – carry incoming information from sense receptors → central nervous system
Motor Neurons – carry outgoing information from central nervous system → muscles/glands
The Peripheral Nervous System
The peripheral nervous system links the central nervous system with the body's sense receptors, muscles, and glands.
Somatic Nervous System – controls the body’s skeletal muscles
Autonomic Nervous System – controls the glands/muscles of internal organs
Sympathetic Nervous System – arouses the body, mobilizing its energy in stressful situations
Parasympathetic Nervous System – calms the body, conserving its energy
The Central Nervous System
The central nervous system enables our humanity—our thinking, feeling, and acting. Its spinal cord is an information highway
connecting the peripheral nervous system to the brain.
Reflex – simple, automatic, inborn response to a sensory stimulus
The Endocrine System
Interconnected with the nervous system is the second of the body's communication systems, the endocrine system - a set of glands
that secrete hormones into the bloodstream.
Hormones – chemical messengers that are produced in one tissue and affect another
Adrenal Glands – secrete the hormones epinephrine and norepinephrine
Pituitary Gland – regulates growth and controls other endocrine glands
Studying the Brain
Clinical Observation
Manipulation
Recording Electrical Activity
Electroencephalogram (EEG) – recording of waves of electrical activity across the brain’s surface
Neuroimaging Techniques
PET Scan – detects where radioactive form of glucose goes while brain performs a given task
MRI – uses magnetic fields to produce images that distinguish among types of soft tissue
fMRI – reveals blood flow; brain activity by comparing successive MRI scans. MRI scans show
brain anatomy; fMRI scans show brain function.
Motor and Sensory Centers
Motor Cortex – located at the rear of the frontal lobe, controls voluntary movement
Sensory Cortex – located at the front of the parietal lobe, registers touch
Language Centers
Broca’s Area – controls language expression
Wernicke’s Area – controls language reception
Aphasia – impairment of language due to brain damage usually in left hemisphere
Brain Structure
Cerebral Cortex – control and information processing center
Frontal Lobe – planning, organ zing, coordinating, reasoning, thinking
Parietal Lobe – sensation
Temporal Lobe – hearing, speaking, and other verbal activity
Occipital Lobe - vision
Limbic System – emotions: fear and aggression; drives: food and sex
Hypothalamus – controls hormones, works with Limbic System
Amygdala – controls fear and emotions
Hippocampus – processes new memories
Basal Ganglia – controls movement
Tectum – works with cerebral cortex to control hearing and vision
Tegmentum – sleep/wake cycle, attention, muscle tone, and reflexes
Cerebellum – motor functions and coordination
Thalamus – relay station or “neural switchboard”
Medulla – vital functions → heartbeat, breathing, movement
Pons – regulates sleep
Splitting the Brain
Clinical evidence has shown that the brain's two sides serve differing functions.
Corpus Callosum – large band of neural fibers connecting the two brain hemispheres and carrying messages between them;
can reduce seizures if severed
Split Brain – a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers between them.
“One Brain or Two?” → Hock Article
Ajeldin T. Huit
Pd: 05
Review for Midterms: Chapter 1.5 Statistical Reasoning
Using statistics, we can organize, summarize and make inferences. Once researchers have gathered the data, they
first organize them. Next is to summarize the data using some measures of central tendency, a single score that
represents a whole set of scores. There are 3 measures of central tendency:
Mode is most frequently occurring score in a distribution.
Mean is arithmetic average-the total sum of all the scores divided by the no. of scores.
Median- is the middle score in a distribution. Half the scores are above and half are below.
Sometimes when a distribution is lopsided or skewed, the mean is inaccurate, which is also called skewed
distribution.
There are 2 measures of variation:
Range is the gap between the lowest and highest scores. An example is a basketball player who scored 13 and 17 pts. in
each of 10 games. The next score would be around 15 pts. because of the player’s range.
Standard deviation is more useful standard for measuring how much scores deviate from one another. It better gauges
whether scores are packed together or dispersed, because it uses information from each score. It is also more informative
than the mean alone.
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There are 3 principles for marking general reactions:
Representative samples are better than biased samples. The best basis for generalizing id not from the exceptional
& memorable cases one finds at the extremes but from a representative samples of cases.
Less-variable observations are more reliable than those that are none reliable.
More cases are better than fewer
Psychologists decide whether differences are meaningful by statistical tests. When sample averages are reliable
and the difference between them is relatively large, the difference is statistical significance. It mean that the difference we
observed is probable not due to chance variation between samples.
Review for Midterms: Chapter 8 Learning by Observation
Observational learning- learning by observing others
An example is when a child who sees his big sister burn her fingers on the stove has thereby learned not to touch it.
Modeling- is the process of observing and imitating a behavior.
Neuroscientists have discovered mirror neurons that provide a neural basis for observational learning. For
example, neurons fire when a monkey performs a task. This also fire when the monkey observes another monkey
performing some task. Humans have mirror neurons too and they help children learn by observation how to mimic lip and
tongue movement when forming new words. Mirror neurons also help give rise to children’s empathy and to their ability to
infer another’s mental state.
Catherine Fisher
AP Psychology
1-15-09
Outline
Ch. 2 – Endocrine System
1. The endocrine communication system is closely interconnected with the nervous system, but it is slower. (Analogy: e-mail =
nervous system, snail-mail = endocrine system). This slower pace explains why we sometimes feel the remnants of high
emotion after the cause for the high emotion is gone. Ultimately it is worth the wait, as the effects of endocrine messages often
out last those of the nervous system.
2. Pituitary Gland: Controlled by the hypothalamus, the pituitary gland is the most influential endocrine gland. It releases
hormones that influence growth and its secretions influence the release of other hormones by other endocrine glands.
3. The glands influence mood, metabolism, growth, etc. and work to keep things balanced when we react to a situation.
Ch. 3 – Gender Identity
1. Sex Matters: Studies suggest that certain parts of the brain develop differently based on sex.
2. Males and females really only differ by one chromosome. Social norms and expectations influence people to identify and act
as either male or female. These norms are what really define gender. Nature defines our sex; nurture defines our gender.
3. The gender we identify with determines the norms we follow and our gender roles. Gender roles determine how males and
females “should act”. Behavior is influenced by this.
I. Adolescence
A. Erikson's stages of Psycho social Development
1. Identity vs. Role Confusion
a. Teenagers work at refining a sense of self by testing roles and then integrating them to form a single identity or they become confused
about who they are.
B. Forming an Identity. And Intimacy.
1. Identity- a self-definition that unifies the various selves into a consistent and comfortable sense of who one is.
2. Finding your identity prepares you for intimacy.
a. Intimacy- the ability to form emotionally close relationships.
3. Once you have a clear and comfortable sense of who you are, you are ready for close relationships.
C. Parent and Peer Influence
1. Adolescence is typically a time of diminishing parental influence and growing peer influence.
2. Teens talk, dress and act more like their peers more than their parents.
3. Parents influence religion, college and career choices.
II. Hearing pg 215
A. The Stimulus Input: Sound waves
1. The strength or amplitude of sound waves determines their loudness.
2. Waves also vary in frequency which determines the pitch.
B. The Ear
1. Outer Ear
a. It channels the sound waves through the auditory canal.
2. Middle Ear
a. Transmits vibrations through three bones.
i. Hammer, anvil, stirrup.
3. Inner Ear
a. Houses the cochlea
C. How do we perceive pitch?
1. Place theory- the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.
2. Frequency theory- the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus
enabling us to sense its pitch.