Psych 105 - Final exam notes

Scientific Method

A set of principles about the appropriate relationship between ideas using empirical evidence; a procedure using empirical evidence to establish fact

• Develop an idea about how something works and then make observations and use them to determine whether or not our idea is true/accurate

Theory vs Hypothesis

1. Explanation of a natural phenomenon; can never be proven right

2. Falsifiable prediction made by a theory

Empiricism

Belief that accurate knowledge can be obtained through observation; essential element in scientific method

Empirical Method

Set of rules and techniques for observation

• People are difficult to study because of their complexity, variability, and reactivity (ex. people can react differently to the same situation)

• Kinds of methods:

  • Methods of observation

  • Methods of explanation

Dogmatism

The tendency to cling to one’s beliefs

Limitations of Observation

• Inconsistent

• Incomplete

• Scientific techniques for overcoming these limitations

  • Measurement 

  • Description

Operational Definition

Description of property in measurable terms (ex. how one chooses to measure happiness in a study - dopamine levels, smiles per hour, etc)

A Good Operational Definition:

• Construct validity: extent to which the thing being measured (ex. smiles) adequately characterizes the property (ex. a person’s happiness)

• Key features of a good detector:

  • Reliability: tendency for a measure to produce the same measurement whenever it is used to measure the same thing

  • Power: ability of a measure to detect conditions specified in the operational definition, as well as ability to detect differences/changes in ex. happiness

2 Steps in Measuring Properties

• Define the property: generate an operational definition that has good construct validity

• Detect the property: design an instrument that has reliability and power

• Ex. power and reliability in the Olympics

  • Two runners crossed the finish line with fractions of a second difference, and without powerful detectors, judges would’ve thought they tied, which they did not

Demand Characteristics

Aspects of an observational setting that cause people to behave as they think someone else wants or expects

• These characteristics make it hard to measure behaviour as it typically unfolds because people may not act as they would in a typical situation

• Psychologists avoid these by observing people without their knowledge

Naturalistic Observation

Technique for gathering scientific information by unobtrusively observing people in their natural environments

• Naturalistic observation is not always practical

  • Some events are not naturally occurring

  • Some events can only be observed through direct interaction 

  • Observer bias may occur

• How do researchers measure “pace of life”?

  • They make naturalistic observations - in this case, measuring the average walking speeds of pedestrians in different cities

Avoiding Demand Characteristics

1. Privacy: people are less likely to be influenced by demand characteristics if they cannot be identified (ex. being told their info is completely anonymous)

2. Control: measuring behaviours that are NOT under a person’s voluntary control (ex. measuring pupil dilation)

3. Unawareness: people can’t try and behave how they should behave if they don’t know how they should behave (ex. signing up for a research study and not knowing the full purpose of the study and not knowing what behaviour they’re looking for)

Observer Bias

Tendency for observers’ expectations to influence what they believe they observed and what they actually observe (ex. how fast rats were going through a maze, some being told their rat is a fast learner and others being told their rat is a slow learner, discrepancies between reported rat speed despite all the rats actually being the same)

• Why does this occur?

  • Expectations can influence observations

  • Expectations can influence reality

• It can be avoided by conducting double-blind studies (researchers AND participants don’t know what is expected of them in the study)

Frequency Distribution

Graphic representation showing the number of times in which the measurement of a property takes on each of its possible values (determine how many people respond to different ratings on a scale)

Normal Distribution

Mathematically defined frequency distribution in which most measurements are concentrated around the middle

Descriptive Statistics

Brief summary statements about essential information from a frequency distribution

• Central tendency:

  • Mean: average of all measurements

  • Median: value that is in the middle of the data

  • Mode: value that is most frequently observed in the measurement

• Skewed distribution

  • Positive skew: mode, median and mean are on the left side

  • Normal distribution: normal bell curve, all 3 m’s are the same

  • Negative skew: mean, median and mode are on the right side

Variability

Extent that measurements differ; tells us how much the measurements differ from each other or roughly how wide the distribution is

Range vs Standard Deviation

1. Value of the largest measurement in a frequency distribution minus the value of the smallest measurement

2. Statistic that describes the average difference between the measurements in frequency distribution and the mean of that distribution

Correlation

Relationship between variables in which variations in the value of one variable are synchronized with variations in the value of the other

Correlation Direction and Strength

• Correlation direction: either positive or negative

  • Positive correlation: more-is-more relationship (ex. education and income)

  • Negative correlation: more-is-less relationship (ex. education and health issues)

• Correlation strength

  • Limited range

    • r ranges

      • -1.0 (perfect negative correlation) 

      • +1.0 (perfect positive correlation) 

      • 0 (no correlation)

• Correlation coefficient: mathematical measure of the direction and strength of a correlation (r)

Third Variable Problem

Natural correlation between two variables cannot be taken as evidence of a causal relationship between them because a third variable might be causing them both

Experimentation

Technique for establishing the causal relationship between variables

• Elimination of differences between groups by examining two key features

Establishing Causal Relationships

• Manipulate independent variable; create at least two conditions

• (independent variable is the one manipulated in an experiment, different levels of independent variable are called conditions (ex. violent and nonviolent exposure))

• Measure dependent variable 

• (dependent variable is measured in the experiment)

• Compare measurements of conditions with each other

Making Different Conditions

1. Manipulation: technique for determining the causal power of a variable by actively changing its value

2. Random assignment: procedure that lets chance assign participants to the experimental or control group

3. Self-selection: problem that occurs when anything about a participant determines whether they will be included in the experimental or control group

Ensuring validity

• Calculating the odds that random assignment has failed each time the experiment is conducted

  • Generally, not accepting experimental results unless the calculation suggests there is less than a 5% chance that those results would have occurred if random assignment had failed

Statistical Significance

Determined when we calculate the odds that random assignment has failed through inferential statistics

• Statistical significance results: p < .05

• Failure of random assignment: p > .05

Internal vs External Validity

1. Attribute of an experiment that allows it to establish causal relationships

   • Operational definitions are vital to determining internal validity

2. Attribute of an experiment in which variables have been operationally defined in a representative way

   • Ability to generalize results to a broader population

Types of Sampling

• Case method: method of gathering scientific knowledge by studying a single individual

• Random sampling: technique for choosing participants to ensure that every member of a population has an equal chance of being included in the sample

  • Sample is representative of population

  • Generalization from sample to population can be made

• Nonrandom sampling: acceptable technique if the similarity between a sample and the population doesn’t matter, when direct replication is available, and if the similarity between the two is a reasonable starting assumption

• Nonrandom sampling is not a fatal flaw in psychological science because:

  • Sometimes the representativeness of a sample doesn’t matter and/or is a reasonable starting assumption

• Learning about some people does not necessarily tell us about all people, but it can still tell us a lot

Replication

Experiment that uses the same procedures as a previous experiment but with a new sample from the same population

• Failure to replicate isn’t necessarily a bad thing (leads to more research) and could mean that the results originally found can only be applied to the conditions present in that particular experiment (ex. one done on people 20-30 but doesn’t apply to the same experiment done on people 60-70)

Types of Errors

• Type I error: error occurs when researchers conclude that there is a causal relationship between two variables when there is not

• Type II error: error occurs when researchers conclude that there is not a causal relationship between two variables when there is (highly dependent on sample size)

Power

The ability to detect a difference if there is a real difference

Critical Thinking

• Involves asking tough questions about the results, study design, other related variables, hypotheses, theories, etc

• Ex. Has evidence been interpreted in an unbiased way? Does the evidence tell not just the truth, but the whole truth? Are we looking at all possible explanations?

We See What We Expect and Want to See

A natural and intuitive way of thinking about evidence worked better for hunter-gatherers than for today’s large-scale, complex societies

• We tend to hold different kinds of evidence to different standards

• Beliefs and desires shape which evidence to consider

• We don’t consider what we don’t see

• The skeptical stance: scientists constantly strive to make their observations more accurate and reasoning more rigorous

Ethical Science

The Tri-Council Policy Statement (TCPS) describes the core principles, based on respect for human dignity, that all research involving human participants must follow

• First, research should show respect for persons and their right to make decisions for and about themselves without undue influence or coercion

• Second, research should show concern for welfare which means that it should attempt to maximize benefits and reduce risks to the participant

• Third, research should be just, which means that it should distribute benefits and risks equally to participants without prejudice towards particular individuals or groups

Respecting People

• Informed consent

• Freedom from coercion

• Protection from harm

• Risk-benefit analysis

• Deception

• Debriefing (includes returning participants to the same emotional state that they came in with)

• Confidentiality

Respecting Animals

• Canadian Council of Animal Care (CCAC) standards for the ethical use and care of animals in research

  • Replacement

  • Reduction

  • Refinement

Respecting Truth

Psychology, like all sciences, works on the honour system

• Results are reported truthfully on what was done and what was found

• Credit is ethically assigned (everyone that contributed to conducting the study should be given credit, depending on their involvement) 

• Data are shared (must have data available to share in the event that someone wishes to review it)

Human Language

• More complex than other forms of communication

• Involves words representing intangible things

• Used to think and conceptualize (different than other animal species)

Phonemes vs Morphemes

1. The smallest units of speech that distinguish one word from another (ex. ba vs pa)

2. The smallest meaningful units of language (ex. the s in dogs)

Phonological vs Morphological rules

1. Indicate how phonemes can be combined to form words

2. Indicate how morphemes can be combined to form words

Syntactic rules vs Telegraphic speech

1. Indicate how words can be combined to form phrases and sentences

2. Sentences that are devoid of function morphemes and consist mostly of content words

Language in Children

• When children learn grammatical rules, they often overregularize them, causing the past tense of run to become runned for example

• Children learn language extremely quickly and make few errors while learning to speak

• Children’s comprehension of language develops faster than their production

• In a study done on internationally adopted preschool children, it was found that their English language progression was the same as infants in English speaking families, however they were able to add to their vocabulary more quickly

Language Progression

Fast Mapping

After 1 time hearing a word, the child learns the word by mapping it onto an underlying concept

Behaviourist Explanation

Language is learned through reinforcement, shaping, extinction, and other basic principles of operant conditioning

• (Cannot actually account for many fundamental characteristics of language development - children generate more than simply what they hear)

Nativist Explanation

Language development is best explained as an innate, biological capacity, and the human brain is said to contain universal grammar (a collection of processes that facilitate language learning)

• Language ability is partly separate from general intelligence

Interactionist Explanation

Although infants are born with an innate ability to acquire language, social interactions play a crucial role in language

Barriers to Acquiring Language

• It has been found that once puberty hits, acquiring language is extremely difficult

• There is a noticeable difference in vocabulary between children growing up in rich vs poor families (~30 million word difference)

• Language development is likely experience-driven rather than a result of general cognitive development

Aphasia

Difficulty in producing or comprehending language

Language Processing in the Brain

Broca’s area: located in the left frontal cortex and is involved in the production of the sequential patterns in vocal and sign languages 

• Broca’s aphasia: despite understanding language fairly well, they have increasing comprehension difficulty as grammatical structures get more complex 

Wernicke’s area: located in the left temporal cortex, involved in language comprehension (spoken or signed)

• Wernicke’s aphasia: individuals can produce grammatical speech (tends to be meaningless), and have considerable difficulty understanding language

Bilingualism

Has sometimes been shown to slow down normal cognitive development, however many variables were not controlled in this study

• Later studies showed that mono and bilingual children do not differ significantly in the course and rate of many aspects of language development

• Bilingualism results denser grey matter in the brain

Right Hemisphere

• There is evidence that the right hemisphere is also involved in language, specifically comprehension

• Damage to the right hemisphere is related to small language comprehension issues

• As the brain matures, specialization of specific neurological structures takes place, which allows the development of language

Blindness and Language

• Blind people activate their visual cortex when making sense of speech whereas people who can see do not

• Blindness from birth has been shown to alter the development of brain specialization

Linguistic Relativity Hypothesis

The idea that language shapes the nature of thought

• Criticized but seen as “half right” (Benjamin Whorf)

• Language can affect how people think about colours as well, depending on how many terms a first language has for colours

Necessary vs Sufficient Condition

1. Something that must be true of the object in order for it to belong to the category (ex. mammal for dog)

2. If it is true of the object, proves that it belongs to the category (ex. German shepherd for dog)

Prototype vs Exemplar Theory

1. The concept that we classify new objects by comparing them to the “best” or “most typical” member of a category

   • More holistic involving image processing (visual cortex)

2. We make category judgements by comparing a new instance with stored memories of other instances of the category

   • Said to do a better job than prototype theory of accounting for certain aspects of categorization

   • Involves analysis and decision making (prefrontal cortex)

Category-Specific Deficit

A neurological syndrome characterized by an inability to recognize objects that belong to a particular category, even when the ability to recognize objects outside of the category is undisturbed

• Deficits usually occur when someone suffers stroke or other trauma to parts of the left hemisphere of the cerebral cortex

Brain Damage

Location of damage to the brain	Impact
Front part of left temporal lobe	Difficulty in identifying humans
Lower left temporal lobe	Difficulty identifying animals
Point at which the temporal meets occipital and parietal	Difficulty retrieving names of tools
Prefrontal lobe	No emotional reactions during risky decision making

**Parietal lobe is responsible for mathematical and spatial reasoning

Rational Choice Theory

The classical view that we make decisions by determining how likely something is to happen, judging the value of the outcome, and then multiplying the two

• People are able to determine frequencies must easier and more accurately than probability

• Ex. people are more likely to buy lottery tickets when the pot gets larger, even though there is a smaller likelihood of winning when compared to a smaller pot with less people buying tickets

Heuristic

A fast and efficient strategy that may facilitate decision making but does not guarantee that a solution will be reached; mental shortcuts that are almost always effective when approaching a problem

Availability Heuristic

A rule of thumb that items that are more readily available in memory are judged as having occurred more frequently

Representativeness Heuristic

A mental shortcut that involves making a probability judgement by comparing an object or event with a prototype of the object or event

Conjunction vs sunk-cost fallacy

1. People think that two events are more likely to occur together than either individual event

2. A framing effect in which people make decisions about a current situation on the basis of what they have previously invested in the situation

Framing Effects

Occur when people give different answers to the same problem depending on how the problem is framed (ex. a drug with a 70% success rate vs a drug with a 30% failure rate)

Optimism Bias

People believe that, compared with other individuals, they are more likely to experience positive events and less likely to experience negative events in the future

• Optimism can be a sign of good psychological adjustment but if there is too much of it, people may not take necessary steps to achieve their goals

Prospect Theory

Propose that people choose to take on risks when evaluating potential losses and to avoid risks when evaluating potential gains

Certainty Effect

People give greater weight to outcomes that are a sure thing

• People are more willing to take risks to avoid losses than to achieve gains

Ill defined vs Well defined problem

1. One that does not have a clear goal or well-defined path(s) to a solution

2. One with clearly specified goals and clearly defined solution paths

Means-End Analysis

A process of searching for the means or steps to reduce the differences between the current situation and the desired goal

• Steps:

  • Analyze the goal state

  • Analyze the current state

  • List the differences between the states

  • Reduce the list of differences by:

    • Direct means

    • Generating a subgoal

    • Finding a familiar problem that has a known solution

Insights

Involve spontaneous restructuring of a problem or unconscious incremental process

• Insight problem solving may be impacted by processing outside conscious awareness

Analogical Problem Solving

Attempts to solve a problem by finding a similar problem with a known solution and applying that solution to the current problem

• Having aha moments is shown in electrical activity in the right temporal area of the brain (anterior cingulate)

Functional Fixedness

The tendency to perceive the functions of objects as unchanging

Reasoning vs Logic

1. A mental activity that consists of organizing information or beliefs into a series of steps in order to reach conclusions (ex. building a house)

2. A system of rules that specifies which conclusions follow from a set of statements; a tool for evaluating reasoning (ex. carpenter’s tools)

Truth vs Validity

• All football players are athletes (truth) 

• LeBron James is an athlete (truth)

• LeBron James is a football player (invalid)

Belief Bias

The idea that people’s judgements about whether to accept conclusions depend more on how believable the conclusions are than on whether the arguments are logically valid

Believability of conclusion > logical validity

Syllogistic Reasoning

• Assesses whether a conclusion follows from two statements that are assumed to be true (ex. LeBron James example)

• It has been found that it is difficult for people to inhibit their pre-existing knowledge and beliefs when reasoning about syllogisms

Illusory Truth Effect

An error in reasoning that occurs when repeated exposure to a statement increases the likelihood that people will judge the statement to be true

Illusion of Explanatory Depth

An illusion that occurs when people overestimate the depth of their understanding

• For example, extreme political views have been shown to sometimes be caused by the illusion of explanatory depth, however once people realized their depth of knowledge was not as deep as they thought, their views moderated

Inappropriate extrapolation

Occurs when you apply results of the study beyond the sample, leading to misleading results/information and inaccurate statements and claims

Intelligence

The ability to use one’s mind to solve novel problems and to learn from experience

Ratio vs Deviation IQ

1. A metric obtained by dividing a child’s mental age by the child’s physical age and then multiplying the quotient by 100

   • A problem with the ratio IQ is that intelligence increases dramatically in the first decade of life but then levels off

2. A metric obtained by dividing a person’s test score by the average test score for people that age and then multiplying the quotient by 100

WISC and WAIS

Wechsler Intelligence Scale for Children and Wechsler Adult Intelligence Scale

• Most widely used intelligence tests

• Measures intelligence by asking people to answer questions and solve problems

  • Verbal comprehension

  • Perceptual reasoning

  • Working memory

  • Processing speed

Intelligence tests

• Sometimes, intelligence tests are problematic because results, if they are low, can sometimes cause people to earn significantly less over their lifetime

• Intelligent people are said to make more money because they often complete more education

• Intelligence is also a good predictor of health and longevity

• Intelligent people are healthier, wealthier, and happier

• Some say intelligent people spread happiness to others

Two factor theory of intelligence

Suggests that a person’s performance on a test is due to a combination of general cognitive ability and specific abilities that are unique to the test

• General cognitive ability: g

• Specific abilities: s

• However, many found that the correlations were stronger between ex. a child’s score on a verbal test and their score on another verbal test vs verbal test and mathematical test, leading to the conclusion that people have primary mental abilities as opposed to general intelligence

• There was a huge reanalysis of data that showed an intelligence hierarchy, which consisted of general ability intelligence which was made up of few middle level abilities

• Charles Spearman

Confirmatory factor analysis

Showed that both Spearman and Thurstone were correct

• Looks for intercorrelations/patterns within correlations

Data based approach

• Says there are two distinct middle-level abilities: physical coordination and academic skill

• John Carroll discovered that there are 8 middle level abilities, including:

  • Memory and learning

  • Visual perception

  • Auditory perception

  • Retrieval ability

  • Cognitive speediness (how fast you can do a task)

  • Processing speed (how fast you can process information)

  • Crystallized intelligence

  • Fluid intelligence

Crystallized vs fluid intelligence

1. The ability to apply knowledge that was acquired through experience, generally measured by tests of vocabulary and factual information

2. The ability to solve and reason about novel problems, generally measured by tests that present people with abstract problems in new domains that must be solved under time pressure

   • *damage to the frontal cortex affects this intelligence

Analytic intelligence

Problem solving, what is measured on IQ tests

Creative intelligence

The ability to generate solutions that other people do not

Practical intelligence

The ability to implement these solutions in everyday settings

Emotional intelligence

The ability to reason about emotions and to use emotions to enhance reasoning

• Emotionally intelligent people tend to be happier, healthier, and more satisfied with their lives

  • They can also identify, describe, and manage their emotions to improve decisions

  • Can identify other people’s emotions from facial expressions and tone of voice

  • Have better social skills and more friends

  • Show less neural activity when solving emotional problems than emotionally unintelligent people do

Intelligence across cultures

• Different cultures have different standards for what they view to be intelligence

• Some argue that every human culture values the ability to solve important problems, and what distinguishes cultures is the kinds of problems that the people who live in them consider important

Origins of intelligence

• Said to be influenced by nature and nurture

• The joint product of innate characteristics and unique experiences

• Some argue that intelligence runs in certain families

Genetic relatedness

• It is questioned whether families have similar levels of intelligence because they share genes, because they share environments or both

• It has been found that IQs of genetically identical twins who were raised in different households are more similar to each other than the IQs of biologically unrelated children who were raised in the same household

Heritability coefficient

A statistic that describes the proportion of the difference between two or more people’s IQ scores that can be explained by differences in their genes (h²)

• It is usually said that roughly 50-70% of the differences between people’s IQ scores is due to genetic differences between those people

• Changes over time and in different environments

• How big of an influence genes have on the differences in a particular group of people’s IQ scores

  • Value of heritability coefficient is different when different groups are measured, as well as depending on the age of the people being measured 

Shared vs nonshared environment

1. Features of the environment that are experienced by all relevant members of a household

2. Features of the environment that are not experienced by all relevant members of a household

Environmental influences on intelligence

• Intelligence is influenced by both genetics and environment

• Because the brain is still growing and changing during adolescence, intelligence can change quite dramatically during this time

• The Flynn Effect states that the average IQ score today is roughly 30 points higher than it was a century ago

• Emotion can affect performance on cognitive tasks

Impacts on intelligence

Poverty Lowers Intelligence

• On average, children who are raised in high SES families have IQs 12-18 points higher than those raised in low SES families

• Low SES may impair brain development (most influential in early childhood)

• May be due to poorer nutrition and medical care, and increased stress

• Also more likely to be exposed to environmental toxins (ex. mercury, lead) 

• High SES families are more likely to provide intellectual stimulation

School Raises Intelligence

• Smart people tend to stay in school, and staying in school makes people smart

• Each additional year of education raises a person’s IQ by about 1-5 points

• The correlation between formal education and intelligence is large (r = 0.55 to 0.90)

• Education may improve test-taking ability rather than general cognitive ability

• Educational effects on intelligence may be small and short-lived, but school produces long-lasting increases in other critical skills

The Malleability of Intelligence

• Motivation can cause people to escape usual times of decline in intelligence

• Effort plays a large role in intelligence and whether it is lost or gained

• Higher IQ people tend to have brains that stay ‘open’ for longer and can change (positive environmental influences) more than those with lower IQs

Gene environment interactions

• Extra chromosomes and mercury are examples of things that affect intelligence

• However, just because someone has a certain gene, the environment they find themselves in may affect whether or not that gene is switched on or off

Individual differences in intelligence

• 68% of people have IQs between 85 and 115

• Males IQ scores seem to be more variable than those of females

• Highly intelligent individuals are less susceptible to mental illness than those of lower intelligence

• Gifted people are often only gifted in one specific area (ex. math, language, or music)

• Researchers have found that gifted children spend a large amount of time partaking in the activity they have a gift in, leading them to believe that a large part of their gift is passion and dedication

• The two most common causes of intellectual disability are down syndrome and fetal alcohol syndrome

• Intellectual disabilities tend to be general, meaning people have difficulty with a wide range of tasks