AP Psych All Units

confirmation bias

tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence

hindsight bias

"I knew it all along"

Overconfidence

Tendency to overestimate our ability to make correct predictions

experiment

A research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process

non-experimental research

research that lacks the manipulation of an independent variable, random assignment of participants to conditions or orders of conditions, or both

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

dependent variable

The measurable effect, outcome, or response in which the research is interested.

random assignment

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups

case study

an observation technique in which one person is studied in depth in the hope of revealing universal principles

Correlation

A measure of the relationship between two variables

meta-analysis

a procedure for statistically combining the results of many different research studies

naturalistic observation

watching behavior in real-world settings without trying to manipulate the situation

Hypothesis

A testable prediction, often implied by a theory

falsifiable

able to be disproven by experimental results

operational definition

a statement of the procedures (operations) used to define research variables

confounding variable

in an experiment, a factor other than the independent variable that might produce an effect

Population

the group of people who will be available for selection in a study

Sample

A relatively small proportion of people who are chosen in a study so as to be representative of the whole.

representative sample

a sample that accurately reflects the characteristics of the population as a whole

random sample

a sample in which every element in the population has an equal chance of being selected

convenience sample

only members of the population who are easily accessible are selected

sampling bias

a flawed sampling process that produces an unrepresentative sample

Generalizability

the extent to which we can claim our findings inform us about a group larger than the one we studied

experimental group

In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable.

control group

the group that does not receive the experimental treatment.

placebo effect

the phenomenon in which the expectations of the participants in a study can influence their behavior

Placebo

something which has a positive mental effect, but no physical effect

single-blind study

study in which the subjects do not know if they are in the experimental or the control group

double-blind procedure

an experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or a placebo.

experimenter bias

phenomenon that occurs when a researcher's expectations or preferences about the outcome of a study influence the results obtained

social desirability bias

the tendency for people to say what they believe is appropriate or acceptable

Qualitative Research

seeks in-depth, open-ended responses, not yes or no answers

Quantitative Research

research that collects and reports data primarily in numerical form

Replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

third variable problem

A problem that occurs when the researcher cannot directly manipulate variables; as a result, the researcher cannot be confident that another, unmeasured variable is not the actual cause of differences in the variables of interest.

structured interview

involves asking each applicant the same questions and comparing their responses to a standardized set of answers

Likert Scale

a way of formatting a survey questionnaire so that the respondent can choose an answer along a continuum

institutional review

process of examining studies for ethical concerns by a committee of peers

informed consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

No harm

a study must not cause psychological, physical, or emotional harm to the participants

Confidentiality

the assurance that individual information is available only to those who are authorized to view it

deception

research in which the participants are misled about the purpose of the research, but is debriefed properly after the study has been done

Debriefing

the post-experimental explanation of a study, including its purpose and any deceptions, to its participants

Histogram

A graph of vertical bars representing the frequency distribution of a set of data.

Scatterplot

a graphical depiction of the relationship between two variables

measure of central tendencies

a single value (mean, median, or mode) that describes the way in which a group of data cluster around a central value.

mean

the arithmetic average of a distribution, obtained by adding the scores and then dividing 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

normal curve (normal distribution)

a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (about 68 percent fall within one standard deviation of it) and fewer and fewer near the extremes.

skewed distribution

When the results are not symmetrical (appears to favor one side over the other)

bimodal distribution

a frequency distribution having two different values that are heavily populated with cases

range

the difference between the highest and lowest scores in a distribution

standard deviation

a measure of variability that describes an average distance of every score from the mean

percentile rank

Percentage of scores falling at or below a specific score.

regression toward the mean

the tendency for extreme or unusual scores to fall back toward their average.

correlation coefficient

a statistical index of the relationship between two things (from -1 to +1)

effect size

the magnitude, or strength, of a relationship between two or more variables

statistical significance (p-value)

a statistical statement of how likely it is that an obtained result occurred by chance

claim

An assertion, usually supported by evidence

heredity

Passing of traits from parents to offspring

nature

the influence of our inherited characteristics on our personality, physical growth, intellectual growth, and social interactions

nurture

external factors that one experiences, such as family interactions or education.

evolutionary perspective of psychology

explores how natural selection affects the expression of behavior and mental processes to increase survival and reproductive success.

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

eugenics

study of factors that influence the hereditary qualities of the human race and ways to improve those qualities

central nervous system

brain and spinal cord; interacts with all processes in the body.

peripheral nervous system

relays messages from the central nervous system to the rest of the body and includes the autonomic and somatic nervous systems.

Autonomic nervous system

governs processes that are involuntary and includes the parasympathetic and sympathetic nervous systems.

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles; governs processes that are voluntary.

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

neurons

neural cells that transmit information

motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

Cell body/Soma

contains the nucleus and other parts of the cell needed to sustain its life

Dendrite

Branchlike parts of a neuron that are specialized to receive information and send it on.

Axon

the neuron extension that conducts messages through its branches away from the cell body to other cells

Axon Terminals/Terminal Buttons

Transmits messages through the other cells; Holds neurotransmitters

Myelin Sheath

Covers the axon of some neurons and helps speed up the transmission of the message

threshold

The minimum level of stimulation required to get a neuron to fire.

action potential

a neural impulse; a brief electrical charge that travels down an axon

resting potential

A neuron at rest is negative and the outside of a neuron's cell membrane is positive.

refractory period

the time following an action potential during which a new action potential cannot be initiated

all-or-nothing principle

Once action potential reaches threshold, either fires or doesn't

synapse/synaptic cleft

Connection site and area of communication between neurons where neurotransmitters are released and info is transmitted from one neuron to the next.

reuptake

a neurotransmitter's reabsorption by the sending neuron

Acetylcholine

enables muscle action, learning, and memory

dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.

Serotonin

Affects mood, hunger, sleep and arousal. Undersupply linked to depression.

Norepinephrine

A neurotransmitter involved in arousal, as well as in learning and mood regulation

GABA

a major inhibitory neurotransmitter; regulates sleep and wake cycles

Glutamate

A major excitatory neurotransmitter; involved in memory

Endorphins

natural, opiatelike neurotransmitters linked to pain control and to pleasure.

Substance P

A neurotransmitter that is involved in the transmission of pain messages to the brain.

excitatory neurotransmitters

chemicals released from the terminal buttons of a neuron that provoke the next neuron into firing

inhibitory neurotransmitters

chemicals released from the terminal buttons of a neuron that prevent the next neuron from firing

Agonist

a molecule that, by binding to a receptor site, stimulates a response

Antagonists (drugs)

These drugs block the actions of neurotransmitters