PSYC 140 Modules 1–8 Comprehensive
Psychology Exam Review 2026/2027 –
Complete Exam-Style Questions with Correct
Answers & Detailed Rationales | Verified &
Reliable
Question 1
A researcher wants to determine whether sleep deprivation
causes poorer performance on a sustained-attention task.
Participants are randomly assigned either to sleep normally or
to remain awake for 24 hours before completing the task.
Which feature of this design most directly permits a causal
conclusion?
A. The use of a standardized attention task
B. The measurement of participants' sleep duration
C. Random assignment to experimental conditions
D. The use of a sufficiently large sample
Rationale: Random assignment helps distribute preexisting
differences among participants across conditions, making the
independent variable—sleep deprivation—the primary
systematic difference between groups. This strengthens the
,inference that differences in attention performance were
caused by the experimental manipulation. Standardized
measurement improves reliability and validity but does not
itself establish causation. Measuring sleep duration can
document whether the manipulation occurred, while a large
sample can improve statistical precision; neither
independently provides the key causal control supplied by
random assignment.
Question 2
A psychologist reports that the correlation between daily stress
scores and hours of sleep is −0.68. Which interpretation is most
accurate?
A. Stress causes people to sleep 68% fewer hours.
B. Higher stress scores tend to be associated with fewer hours
of sleep.
C. Sixty-eight percent of participants with high stress have sleep
problems.
D. Sleep deprivation causes stress in 68% of participants.
Rationale: A correlation of −0.68 indicates a fairly strong
negative linear association: as one variable increases, the
other tends to decrease. Correlation alone does not establish
causation, so the finding cannot demonstrate that stress
causes reduced sleep or that reduced sleep causes stress. The
numerical value also does not represent a percentage of
,participants or a percentage reduction in sleep. Establishing a
causal relationship would require an appropriate
experimental or carefully designed longitudinal approach.
Question 3
A questionnaire intended to measure depression produces
nearly identical scores when the same individuals complete it
one week apart, but it correlates poorly with established
measures of depressive symptoms. Which property is
demonstrated more strongly than validity?
A. External validity
B. Construct validity
C. Reliability
D. Ecological validity
Rationale: Reliability concerns the consistency or stability of
measurement. Similar scores across repeated administrations
demonstrate test–retest reliability. Validity concerns whether
the instrument actually measures what it claims to measure.
Because the questionnaire correlates poorly with established
measures of depression, evidence for convergent or construct
validity is weak. External and ecological validity concern the
generalizability of findings rather than the consistency of a
measurement instrument.
Question 4
, Which situation best illustrates the principle of informed
consent in psychological research?
A. Participants are told only that the study is about human
behavior.
B. Participants are automatically enrolled because the research
has scientific value.
C. Participants receive relevant information about the study
and voluntarily agree to participate.
D. Participants are informed of the hypothesis only after
completing the experiment.
Rationale: Informed consent requires prospective participants
to receive sufficient information about the research, including
relevant procedures, risks, benefits, and their rights, so that
participation can be voluntary and informed. Researchers may
sometimes withhold the precise hypothesis when necessary to
prevent expectancy effects, but that does not eliminate the
broader informed-consent requirements. Scientific importance
does not justify compulsory participation, and post-study
disclosure alone does not constitute informed consent.
Question 5
A neuron receives several excitatory signals from different
presynaptic neurons at approximately the same time. The
combined effect brings the membrane potential to threshold.
This process is best described as:
Psychology Exam Review 2026/2027 –
Complete Exam-Style Questions with Correct
Answers & Detailed Rationales | Verified &
Reliable
Question 1
A researcher wants to determine whether sleep deprivation
causes poorer performance on a sustained-attention task.
Participants are randomly assigned either to sleep normally or
to remain awake for 24 hours before completing the task.
Which feature of this design most directly permits a causal
conclusion?
A. The use of a standardized attention task
B. The measurement of participants' sleep duration
C. Random assignment to experimental conditions
D. The use of a sufficiently large sample
Rationale: Random assignment helps distribute preexisting
differences among participants across conditions, making the
independent variable—sleep deprivation—the primary
systematic difference between groups. This strengthens the
,inference that differences in attention performance were
caused by the experimental manipulation. Standardized
measurement improves reliability and validity but does not
itself establish causation. Measuring sleep duration can
document whether the manipulation occurred, while a large
sample can improve statistical precision; neither
independently provides the key causal control supplied by
random assignment.
Question 2
A psychologist reports that the correlation between daily stress
scores and hours of sleep is −0.68. Which interpretation is most
accurate?
A. Stress causes people to sleep 68% fewer hours.
B. Higher stress scores tend to be associated with fewer hours
of sleep.
C. Sixty-eight percent of participants with high stress have sleep
problems.
D. Sleep deprivation causes stress in 68% of participants.
Rationale: A correlation of −0.68 indicates a fairly strong
negative linear association: as one variable increases, the
other tends to decrease. Correlation alone does not establish
causation, so the finding cannot demonstrate that stress
causes reduced sleep or that reduced sleep causes stress. The
numerical value also does not represent a percentage of
,participants or a percentage reduction in sleep. Establishing a
causal relationship would require an appropriate
experimental or carefully designed longitudinal approach.
Question 3
A questionnaire intended to measure depression produces
nearly identical scores when the same individuals complete it
one week apart, but it correlates poorly with established
measures of depressive symptoms. Which property is
demonstrated more strongly than validity?
A. External validity
B. Construct validity
C. Reliability
D. Ecological validity
Rationale: Reliability concerns the consistency or stability of
measurement. Similar scores across repeated administrations
demonstrate test–retest reliability. Validity concerns whether
the instrument actually measures what it claims to measure.
Because the questionnaire correlates poorly with established
measures of depression, evidence for convergent or construct
validity is weak. External and ecological validity concern the
generalizability of findings rather than the consistency of a
measurement instrument.
Question 4
, Which situation best illustrates the principle of informed
consent in psychological research?
A. Participants are told only that the study is about human
behavior.
B. Participants are automatically enrolled because the research
has scientific value.
C. Participants receive relevant information about the study
and voluntarily agree to participate.
D. Participants are informed of the hypothesis only after
completing the experiment.
Rationale: Informed consent requires prospective participants
to receive sufficient information about the research, including
relevant procedures, risks, benefits, and their rights, so that
participation can be voluntary and informed. Researchers may
sometimes withhold the precise hypothesis when necessary to
prevent expectancy effects, but that does not eliminate the
broader informed-consent requirements. Scientific importance
does not justify compulsory participation, and post-study
disclosure alone does not constitute informed consent.
Question 5
A neuron receives several excitatory signals from different
presynaptic neurons at approximately the same time. The
combined effect brings the membrane potential to threshold.
This process is best described as:
