Psychology 101

Part 1 - The History and Scope of Psychology

  • What is Psychology?

The scientific study of behavioral and mental processes.

(It's a science, uses critical thinking skills, multiple schools of thought, & has multiple subfields)

  • Empirical approach

Empirical : verifiable by observation or experience rather than theory or pure logic

Empirical Approach : an evidence-based method that draws on observation and experimentation

  • What is critical thinking?

Examine assumptions, appraises the source, discerns hidden bias, evaluates evidence, & assesses conclusions

(“The problem with quotes on the internet is that you never know if they're true.” - Abraham Lincoln)

  • Psychology origins : Philosophy and Medicine

  • Functionalism

(William James 1842-1910)

How mental and behavioral processes functions

  • Structuralism

(Edward Titchener 1867-1927)

Uses introspection to reveal the structure of the human mind

  • Women in psychology : 

  • First female president of the american psychological association

(Mary Whiton Calkins 1863)

  • First woman to earn a Ph.D. in psychology

(Margaret Floy Washburn 1871-1939)

  • Three different ways psychology explains behaviors

(schools of psychology)

  • Behaviorism : psychology should studies behavior, not references to mental processes

  • Psychoanalysis : Focuses on unconscious mental processes and early childhood experiences

  • Humanistic : Focuses on human growth potential, and the need for love and acceptance

  • W.E.I.R.D

  • Western

  • Educated

  • Industrial

  • Rich

  • Democratic

(“All people are the same; only their habits differ” - Confucius, 551-497 b.c.e.)

  • Levels of Analysis

  • The biopsychosocial approach integrates 3 levels of analysis

  1. Biological

  2. Psychological

  3. Sociocultural

(“Like 2-dimensional views of a 3-dimensional object, each of psychology’s perspectives is helpful each by itself fails to reveal the whole picture.”)

  • Subfields of Psychology

  • Biological

  • Developmental

  • Cognitive

  • Social

  • Industrial / Organizational (I.O.)

(& more)

Part 2 - Research Strategies : How Psychologists Ask and Answer Questions

  • Isn’t psychology just common sense??

  • 3 Flaws of commonsense thinking:

  • Hindsight bias : The tendency to perceive past events as something more predictable than they are

  • Perceiving order in random events

  • Overconfidence

(“Dunning-Kruger Effect” / “Knew it all along”) 

  • What is the scientific method?

The self-correcting process that asks questions and observes the answers

Theories -> Hypotheses -> Research / Observations {confirm, reject revise} -> (start it over)

  • Theory : an explanation using principles that organize observations and predict behaviors / events

  • Hypothesis : a testable prediction, implied by a theory

  • Operational Definition : statement of the exact procedures (operations) used in a research study.

  • Peer Reviewer : scientists who evaluate a study’s theory, originality, and accuracy

  • Replication : repeating the essence of a research study and determining whether the finding is reproduced

  • Preregistration : to publicly communicate a planned study design, hypotheses, data collection, & analyses

  • Meta-analysis : a statistical procedure for analyzing the results of multiple studies to reach an overall conclusion

  • 3 ways of conducting psychological research

  • Descriptive : 

To observe and record behavior (basic purpose)

Do case studies, naturalistic observations or surveys (how conducted)

Nothing (whats manipulated)

No control of variables; single cases may be misleading (weakness)

  • Correlational : 

To detect naturally occurring relationships; to assess how well one variable predicts another(basic purpose)

Collect data on two or more variables

Nothing (whats manipulated)

No control of variables; single cases may be misleading (weakness)

  • Experimental : 

To explore cause and effect (basic purpose)

Manipulate one or more variables; use random assignments (how conducted)

The independent variable(s) (what is manipulated)

Sometimes not feasible; results may not generalize to other contexts; not ethical to manipulate certain variables (weakness)

  • Descriptive research methods

  • Case study : individual or group in depth study; can reveal universal principles

  • Natural observation : observing + recording behaviors without manipulating the situation

  • Survey : self-reported attitudes / behaviors; often questions a representative random sample of a larger group

(surveys are incredibly useful but can be tricky…)

Wording of questions

Social desirability

Random sampling

Sampling bias

  • Correlational research methods

  • Correlation : a measure of the extent that 2 factors vary together; if one factor predicts the other

  • Correlation coefficient : a statistical index {1} of the relationship between things on a scale of -1.00 to 1.00

(same direction is positive correlations)

  • Scatterplot : a graphed cluster of dots, each of which represents the value of two variables

(less scatter = stronger correlation)

(no correlation = 0.0)

  • Why correlations can be misleading

  • Illusory Correlations : perceiving a relationship where none exists, or a stronger than-actual relationship

  • Regression Toward the Mean : extreme outcomes usually return closer to average

  • Important to note

(most important thing…)

Correlation DOES NOT imply causation

Correlation can suggest a possible cause-effect relationship, but it does not prove it

  • Experimental research methods

  • Experimental : explore cause and effect through manipulation of 1+ factors and using random assignment

  • Experiment : 1+ factors (IV) are manipulated it’s effect on some behavior or process (DV) is observed

  • Experimental Group : the group exposed to the treatment in an experiment

  • Control Group : the group not exposed to the treatment; serves as a comparison for evaluating the effect of treatment

  • Random assignments : assigning participants to the experimental and control groups by chances, thus minimizing preexisting differences between the groups

  • What makes an experiment and experiment?

  1. manipulation of treatment variable

  2. random assignment

  • Common procedures

  • Double-Blind Procedure : both participants and researchers are blind to which participants are in treatment groups

  • Placebo : fake treatment with no active ingredient

  • Placebo Effect : positive results of a placebo due to positive expectations

  • Research variables

  • Independent variable (IV) : the manipulated factor whose effect is being studied

  • Condoning variable : variable other than the variable being studied that influences the study’s results

  • Dependent variable (DV) : the outcome factor that is measured, expected to change as a result of the independent variable

  • Ethics in psychology

  • Research ethics

Code of ethics laid out by the american psychological association (apa)

  • Animal Research

Researchers must provide “humane care and healthful conditions,” and testing should “minimize discomfort” (per APA) - Plans to conduct animal research must first be reviewed and institutional animal care and used committee (IACUC)

  • (video notes)

  • Research ethics / human research

  • Institutional review board (IRB) : committee that reviews / approves research ensuring rights, safety, and welfare of human participants

  • Informed consent : detailed info about a study given to potential participants allowing them an informed decision of whether or not to participate

  • Debriefing : the post - experimental explanation of a study, including its purpose and any use of deception

Part 3 - Statistical Reasoning in Everyday Life

  • Why statistics matter

  • How do psychologists summarize large amounts of data?

  • Describing data

  • Descriptive statistics : using statistical methods to provide a simple summary of data

  • Measures of central tendency

  • Mean : the average of a distribution, obtained by adding scores and then dividing them by the number of scores

  • Median : the middle score in a distribution; half the scores are above it and half are below it

  • Mode : the most frequently occurring score(s) in a distribution   [ o = often ]

  • Measure of central tendency (image)

  • Describing data : 

  • Measures of variation

Range 

  • The difference between the highest and lowest scores in a distribution 



Standard deviation 

  • A computed measure of how much scores vary around the mean score 



Normal curve 

  • A symmetrical bell shaped curve that describes the distribution of many types of data; most scores fall near the means and fewer around the extremes 



Inferential statistics uses data from a sample to inform us about a larger population 



Alternative hypothesis 

  • A difference does exist between groups between our groups, meaning our IV likely had an effect 



Null hypothesis 

  • Assumes no differences exist between the groups being studied, meaning our IV had no effect 



Statistical significance 

  • How likely a result occurred by chance; standard for results being significant is if this chance is less than 5%

If the above is not true we can reject the null if not we fail to reject or retain the null hypothesis 



Even if the probability of your results being due to chance is low 









Chapter 2 : Biology of the Mind 



Neuron - a nerve cell; the basic building block of the nervous system 



Dendrites - receive incoming messages 



Cell body (soma) - contains the nucleus; maintains the cell 



Axon - carries messages away from the cell body 



Myelin sheath - fatty tissue layer that insulates the axon and speeds neural impulses 



Terminal branches/buttons - send messages to other neurons, muscles, or glands 



Glial cells - nourish, protect, and insulate neurons (worker bees) 



Neurons transmit signals to communicate →Gila supports transmission of these signals 



Action potential - a brief electrical impulse that travels down the axon 



  • Stronger stimulus does not equal a stronger action potential 



  • Stronger stimulus = more frequent firing 



Synthetic gap - tiny space between the sending and receiving neurons 



How the messages crosses: 



Action potential reaches the axon terminal 

↓

Neurotransmitters are released 

↓

Neurotransmitters cross the synthetic gap 

↓

Neurotransmitters bind to the receiving neuron receptors 

↓

The receiving neuron either fires or is inhabited 



Neurotransmitters

  • Chemical messengers released from the sending neuron 

  • Released when action potential reaches terminal 

  • Travel across the synthetic gap 

  • Bind to receptor sites on receiving neuron 



Excitatory = GO 

  • Increases the likelihood that receiving neuron will fire 



Inhibitory = STOP 

  • Decreases the likelihood that the receiving neuron will fire 



Major Neurotransmitters



Acetylcholine 

  • Muscle action 

  • Learning and memory 



Dopamine 

  • Movement 

  • Reward 



Serotonin 

  • Mood 

  • Sleep 



Norepinephrine 

  • Alertness / arousal 



GABA 

  • Major inhibitory neurotransmitters



Glutamate 

  • Major excitatory neurotransmitters



Endorphins 

  • Pain relief and pleasure 



Reuptake: process by which excess neurotransmitters are reabsorbed by the sending neuron or….

  • Broken down by the enzymes 

  • Drift away from the synapse 



SSRI = Selective Serotonin Reuptake Inhibitor 

  • Common class of antidepressant medication 



EX: If reuptake is blocked, serotonin stays available in the synapses longer (can help with depression) 



Agonist 

  • Increases a neurotransmitter’s action by mimicking it or enhancing its effects 



Antagonist 

  • Decreases a neurotransmitter’s action by blocking its effects 





The Nervous System 



Central Nervous System 

  • Brain 

  • Spinal cord 



Peripheral Nervous System 

  • Connects to the rest of the body 



  • Sensory neurons → information to the CNS 

  • Motor neurons → information from the CNS 

Somatic Nervous System 

  • Controls voluntary movement of skeletal muscles 

  • Carries sensory information to the CNS 



Autonomic Nervous System 

  • Controls involuntary functions 

  • Regulates glands and intestinal organs 



Sympathetic system 

  • Arouses the body 

  • Fight-or-flight 

  • Think: Gas pedal 

                     ← Together they maintain homeostasis 

Parasympathetic 

  • Calms the body 

  • Rest-and-digest

  • Think: brake 



Endocrine system 



Hormones: chemical messengers that influence behavior and bodily functions 

  • Longer lasting impacts 

  • Slower release 



Pituitary gland = Master Gland 



EEG - records electrical brain activity 

MRI - detailed brain structure 

PET - shows areas of brain activity using glucose 

FMRI - shows brain/activity



Major Brain Structures  



Brain stem 

  • Basic survival functions 

  • Heartbeat and breathing 

Thalamus 

  • Sensory relay station 



Reticular formation 

  • Arousal and alertness



Cerebellum

  • Coordination and balance 



Limbic system 

  • Involved in emotion, motivation, and memory 

  • Hypothalmus 

  • Pituitary gland

  • Amygdala 

  • Hippocampus 



Amygdala 

  • Fear and aggression

  • Emotional processing 



Hippocampus 

  • Formation of explicit memories 



Pituitary gland 

  • Regulates growth and controls other endocrine glands 

  • Under the influence of the hypothalamus 



Hypothalamus

  • Directs “maintain activities” (eating, drinking, body temperature) 

  • Manages endocrine system via the pituitary gland 

  • Linked to emotion and reward 



The cerebral cortex 

  • Outer layer of the brain involved in complex information processing 




LOBES 

  • Frontal : planning, judgement, movement 

  • Parietal : touch and spatial processing 

  • Occipital : vision 

  • Temporal : hearing and language 



Motor Cortex 

  • Controls voluntary movement 

  • Located in frontal lobe



Somatasensory Cortex 

  • Processes touch/body sensations 

  • Located in parietal lobe 



Association areas 

  • Not primarily involved in basic sensory or motor functions 

  • Support higher mental functions 

  • Learning

  • Memory

  • Thinking

  • Judgement 

  • Language 



Prefrontal cortex

  • Planning

  • Decisions-making

  • Impulse control 



Damage to a different brain areas can produce different changes in behavior. 



Neuroplasticity - the brain’s ability to change and reorganize in response to experience or damage 

  • Learning changes the brain 

  • Practice strengthens neural connections 

  • Some functions can reorganize following damage 



Left and Right Hemispheres 

  • Connected by the corpus callosum 

  • Work together to process information 



Corpus Callosum

  • Large band of neural fibers connecting hemispheres 



Lateralization - some functioning is associated more often with one hemisphere than the other - MYTH 



Split-brain surgery : corpus callosum is severed 

  • Historically used to reduce severe seizures  

  • Helped researchers study hemispheric specialization 



Neurogenesis 

  • Producing new neurons that may mature more and grow larger than the neurons we are born with 




Nature vs. Nurture 



Heredity - the genetic transfer of characteristics from parents to offspring



Environment - every nongenetic influence, from prenatal nutrition to the people and things around us 



Our Genetic Codes of Life 

  • Genes → DNA → Chromosomes 



DNA - DEOXYRIBONUCLEIC ACID 

  • A complex molecule containing the genetic information that makes up the chromosomes 

  • Consists of adenine, thymine, cytosine, and guanine 





Genes - instructions 

  • The biochemical units of heredity that make up the chromosomes; small segments of DNA capable of synthesizing proteins 

  • We have 20k genes; yet not all are active 



Chromosomes - organized packages 

  • Threadlike structures made of DNA molecules that contains the genes 

  • We have 46 chromosomes, one set comes from each parent 

  • XY - male 

  • XX - female     

  • Both are decided by the sperm 



Genome - library 

  • The complete instructions for making an organism, consisting of all genetic material in that organism’s chromosomes 



How it all fits:



  1. DNA “letters” 

  2. Genes “one recipe”

  3. Chromosomes “one cookbook” 

  4. Genome “entire library of cookbooks” 



Takeaways : 

  • We cannot ethically control people’s genetics and environment so we rely on twin and adoption studies as natural experiments 

  • Identical twin → share 100% of their genes 

  • Fraternal twins → share about 50% of their genes 



Heredity vs. heritability 

  • The proportion of variation among individuals in a group that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied. 



Temperament 

  • A person’s characteristic emotional reactivity and intensity 

Takeaways:

  • Heredity is NOT a fixed number 

  • High heritability does NOT explain group differences 

  • Genes do not act alone, environment can shift behavior 

  • Adaptation



Molecular behavior genetics 

  • The study of how genes interact with the environment to influence behavior 

  • Shows how biology and environment meet at the molecular level 



Epigenetics - the study of how environmental factors turn genes on or off without changing the DNA itself 

  • Life experiences add “epigenetic marks” (chemical tags) to DNA 

  • The marks act like signals that tell the cell “use this gene” → turn on or “ignore this gene” → turn it off 



Natural Selection 

  • The principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will (in a competition with other trait variations) most likely be passed on to succeeding generations 



Adaptation 

  • A trait, physical or behavioral that improves chances in a particular environment. It is essentially the response to natural selection. 



Takeaways:

  • Humans are more similar than different 

  • Natural selection shapes our universal tendencies 

  • Many psychological traits are adaptations 

  • Evolution prepared us for the past, not always the present 

  • Culture builds on these biological tendencies 



Criticisms 

  • Because evolution was so long ago it is hard to specifically test hypothesis and finding out the 100% truth 

  • Correlation does not equal causation 

MAJOIR takeaway 

  • Evolution explains tendencies not destiny 

  • Evolutionary psychology offers one way to explain human behavior 

  • These explanations should be evaluated carefully 

  • Biology can influence behavior, but it does not fully determine behavior 

  • Culture, learning, and personal experience also shape sexuality and relationships 



Evolutionary explanation of human sexuality 

  • Reproductive challenges shaped preferences 

  • Men and women are more similar than different 

  • Sexual overperception bias 

  • Evolution does not always serve us in the present 



Parents 

  • Shape early experiences/opportunities 

  • Influence values and behavior 



Peers

  • Influence attitudes, interests, and social norms 



Puberty 

  • period of sexual maturation when a person becomes capable of reproduction 



Testosterone 

  • Present in all people, but typically higher in males 

  • Contributes to male sexual development 

  • Associated with facial hair, deeper voice, and muscle growth 



Estrogen 

  • Present in all people, higher in women 

  • Contributes to female sexual development 

  • Associated with breast development 





Biological sex

  • Biological characteristics 

  • Influenced by chromosomes, hormones, and anatomy 



Gender

  • Social and psychological aspects of identity 

  • Influenced by culture, society, and personal identity 



Primary sex characteristics: reproductive organs 



Secondary sex characteristics: physical features that distinguish the sexes and emerge at puberty 



Gender (nature vs Nurture) 



Nature

  • Focuses on the biological factors that may influence gender (genes, hormones, brain development, evolutionary influences) tied to reproduction



Nurture 

  • Focuses on how society and culture shape gender roles and identity (parenting expectations, media messages, peer influence/social reinforcement, culture definitions of gender roles



Culture

  • The behaviors, ideas, attitudes, values, and traditions shared by a group of people 



Culture shock

  • Is the feeling of confusion, stress, discomfort, or anxiety that people may experience when they are exposed to a culture that is significantly different from their own 



Collectivistic 

  • Emphasizes group goals, cooperation, maintaining harmony within the family or community 

Individualistic 

  • Emphasizes personal goals, independence, and individual achievement 



Culture and gender diversity 

  • Culture shapes how biological tendencies are expressed 

  • Gender differences are influenced by both biology and culture 

  • Humans are highly adaptable 

  • Nature and nurture work together, not against each other