hindsight bias
the tendency to believe, after learning an outcome, that one would have foreseen it
critical thinking
thinking that does not blindly accept arguments and conclusions. rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions.
theory
an explanation using an integrated set of principles that organizes observations and predicts behaviors or events
hypothesis
a testable prediction, often implied by a theory
operational definition
a statement of the procedures (operations) used to define research variables. For example, human intelligence may be operationally defined as what an intelligence test measures
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.
case study
an observation technique in which one person is studied in depth in the hope of revealing universal principles
survey
a technique for ascertaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them.
false consensus effect
the tendency to overestimate the extent to which others share our beliefs and behaviors
population
all the cases in a group, from which samples may be drawn for a study
random sample
a sample that fairly represents a population because each member has an equal chance of inclusion
naturalistic observation
observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation
correlation
a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other. The correlation coefficient is the mathematical expression of the relationship, ranging from -1 to +1
scatterplot
a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation). (Also called a scattergram or scatter diagram.)
illusory correlation
the perception of a relationship where none exists
experiment
A research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors.
double-blind procedure
an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.
placebo effect
experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which is assumed to be an active agent
experimental condition
the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable
control condition
the condition of an experiment that contrasts with the experimental condition and serves as a comparison for evaluating the effect of the treatment
random assignment
assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups
independent variable
The experimental factor that is manipulated; the variable whose effect is being studied.
dependent variable
the outcome factor; the variable that may change in response to manipulations of the independent variable
mode
the most frequently occurring score(s) in a distribution
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
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
statistical significance
a statistical statement of how likely it is that an obtained result occurred by chance
culture
the enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next
Hindsight Bias
I-knew-it-all-along-phenomenon People believe that they knew something all along after an event happens .
Critical Thinking
Thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions.
Theory
An explanation using integrated sets of principles that organizes observations and predicts behaviors or events.
Hypothesis
A testable prediction often implied by a theory.
Operational Definition
Statement of the procedures (operations) used to define research variables.
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.
Survey
A technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.
Population
All the cases in a group being studied, from which samples may be drawn.
Random Sample
A sample that fairly represents a population because each member has an equal chance of inclusion.
Naturalistic Observation
Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.
Correlation
A measure of the extent to which two factors vary together, and thus how well either factor predicts the other.
Correlation Coefficient
A statistical index of the relationship of two things.
Scatterplot
A graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation.
Illusory Correlation
The perception of a relationship where none exists.
Experiment
A research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental processes. By random assignment of participants, the experimenter aims to control other relevant factors.
Random Assignment
Assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to different groups.
Double-Blind Procedure
An experiment procedure in which both the research participants and research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.
Placebo Effect
Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.
Experimental Group
The group that is exposed to the treatment, that is, to one version of the independent variable.
Independent Variable
The experimental factor that is manipulated, the variable whose effect is being studied.
Confounding (Third) Variable
A factor other than the independent variable that might produce an effect in an experiment.
Dependent Variable
The outcome factor; the variable that may change in response to manipulations of the independent variable.
Mean
The arithmetic average of a distribution, obtained by adding the score s 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.
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 described the distribution of many types of data; most scores fall towards the mean and few near the extremes.
Statistical Significance
A statistical statement of how likely it is that an obtained result occurred by chance.
Culture
The enduring behaviors, ideas, attitudes, and traditions shared by a group of people and transmitted from one generation to the next.
Informed Consent
An ethical principle that research participants be told enough to enable them to choose whether they with to participate.
Debriefing
The post experimental explanation of a study, including its purpose and any deceptions to its participants.
case study
an observation technique in which one person is studied in depth in hope of revealing universal principals
control group
in an experiment the group that is not exposed to the treatment , serves as a comparison for the experimental group
mode
the most frequently occurring scores in a distribution
biological psychology
a branch of psychology concerned with the links between biology and behavior.
neuron
a nerve cell; the basic building block of the nervous system.
sensory neurons
neurons that carry incoming information from the sensory receptors to the brain and spinal cord.
motor neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
interneurons
neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.
dendrite
the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.
axon
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands.
myelin sheath
a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.
action potential
a neural impulse; a brief electrical charge that travels down an axon.
threshold
the level of stimulation required to trigger a neural impulse.
synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.
neurotransmitters
chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
reuptake
a neurotransmitter's reabsorption by the sending neuron.
endorphins
"morphine within"—natural, opiatelike neurotransmitters linked to pain control and to pleasure.
nervous system
the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
central nervous system (CNS)
the brain and spinal cord. (Myers Psychology for AP 1e p. 059)
peripheral nervous system (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body. (Myers Psychology for AP 1e p. 059)
nerves
bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs. (Myers Psychology for AP 1e p. 059)
somatic nervous system
the division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system. (Myers Psychology for AP 1e p. 059)
autonomic nervous system
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
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.
reflex
a simple, automatic response to a sensory stimulus, such as the knee-jerk response.
endocrine system
the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.
hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.
adrenal glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
pituitary gland
the endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.
lesion
tissue destruction. A naturally or experimentally caused destruction of brain tissue.
electroencephalogram (EEG)
an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.
CT (computed tomography) scan
a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body. Also called CAT scan.
PET (positron emission tomography) scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.
MRI (magnetic resonance imaging)
a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. They scans show brain anatomy.
fMRI (functional MRI)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. These scans show brain function.
brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; It is responsible for automatic survival functions.
medulla
the base of the brainstem; controls heartbeat and breathing.
reticular formation
a nerve network in the brainstem that plays an important role in controlling arousal.