AP Psychology Unit 1 practice questions
Try 10 multiple-choice questions from Unit 1 here. Pick an answer to see why it's right or wrong, then take the timed test above for a full AP-style set.
Question 1
Source:Adapted from Drug and alcohol dependence. Verweij et al. (2018). Heritability of lifetime ecstasy use.
Researchers investigated the extent to which genetic factors influence lifetime ecstasy use. The sample comprised 8,500 twins and siblings aged between 18 and 45 years from 5,402 families registered at the Netherlands Twin Registry. Participants filled out a questionnaire that included a question about whether they had ever used ecstasy during their lifetime. The researchers used a classical twin design to determine what proportion of individual differences in ecstasy use could be attributed to genetic factors, shared environmental factors, and other residual factors. Twin pairs included both identical twins, who share 100% of their DNA, and fraternal twins, who share approximately 50% of their DNA like any sibling pair. The researchers then analyzed the data to estimate the heritability of lifetime ecstasy use by comparing how similar identical twins were to each other compared to how similar fraternal twins were to each other.
Factor Percentage of Individual Differences Explained Genetic factors 74% Shared environmental factors 5% Residual factors 21% Which of the following best explains why the researchers cannot establish a direct cause-and-effect relationship between genetics and ecstasy use?
The study relies on measuring naturally occurring variables without experimental manipulation.
The researchers utilized self-report questionnaires rather than direct physiological drug testing.
The sample includes both identical and fraternal twins from the same registry.
The residual factors account for a significant portion of the individual differences.
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Answer: (A)
Experimental designs require the manipulation of an independent variable and random assignment to establish cause-and-effect relationships. The described twin study measures naturally occurring genetic similarities and self-reported behaviors, making it a correlational design that can only identify predictive relationships between heredity and drug use.
Question 2
An adoption study tracked personality trait scores (extraversion) for 80 adopted children, their biological parents, and their adoptive parents. The correlation between adopted children and biological parents was r = 0.42; between adopted children and adoptive parents was r = 0.31. Based on these data, which conclusion about the heredity-environment interaction is most appropriate?
Extraversion shows moderate genetic influence, but adoptive family environment also contributes to personality expression
Extraversion is primarily determined by adoptive family environment, as shown by the correlation with adoptive parents
Genetic factors have no meaningful influence on extraversion because the correlation with biological parents is below 0.50
Adoptive parents have stronger genetic influence on extraversion than biological parents because they directly raise the children
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Answer: (A)
The higher correlation with biological parents (0.42) than adoptive parents (0.31) indicates genetic contribution to extraversion, since adopted children share genes but not environment with biological parents. However, the substantial correlation with adoptive parents (0.31) demonstrates environmental influence despite no genetic relationship. This pattern exemplifies LO 1.1.A by showing heredity and environment both shape personality independently.
Question 3
A study tracked temperament (activity level) in 100 identical twin pairs from infancy through age 10. At age 1, twins showed correlation r = 0.78. At age 5, correlation was r = 0.71. At age 10, correlation was r = 0.64. What does the declining correlation pattern suggest about the heredity-environment interaction across development?
Accumulated environmental experiences increasingly differentiate genetically identical individuals as they develop
Genetic influence on temperament decreases with age because environmental factors gradually replace genetic control
Identical twins become genetically more different over time, explaining why their temperament correlation declines
The declining correlation demonstrates that heredity has no meaningful influence on temperament because the correlation is not stable
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Answer: (A)
The declining identical twin correlation (0.78 → 0.71 → 0.64) indicates that despite genetic identity, twins become increasingly different over time. This pattern reflects accumulating environmental influences: different friendships, school experiences, activities, and life events gradually shape temperament expression differently in each twin. This demonstrates LO 1.1.A by showing that heredity provides initial similarity but environment increasingly modulates behavioral expression across development.
Question 4
A family study examined risk for depression across relatives with varying genetic and environmental similarity. The data show: identical twins raised together 67%, identical twins raised apart 45%, fraternal twins raised together 38%, biological siblings raised together 32%, adoptive siblings raised together 15%. What pattern best illustrates how heredity and environment jointly influence depression risk?
Both genetic similarity and shared environment contribute to depression risk, with genetic factors showing stronger influence
Shared family environment is the primary determinant of depression risk because all family members show higher rates than adoptive siblings
Depression risk is determined entirely by genetics because identical twins show the highest concordance rates
Biological siblings raised together show higher depression risk than fraternal twins raised together because they share more genes
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Answer: (A)
Identical twins raised together (67%) exceed identical twins raised apart (45%), demonstrating shared environment adds to genetic influence. However, identical twins raised apart (45%) substantially exceed adoptive siblings raised together (15%), indicating genetic factors contribute more than shared environment alone. The pattern shows heredity and environment both matter, but genetic similarity produces larger risk differences. This demonstrates LO 1.1.A by showing their interactive contribution rather than independent effects.
Question 5
A study examined the heritability of risk-taking behavior in 150 identical twin pairs and 150 fraternal twin pairs, all recruited from college populations. Identical twins showed correlation r = 0.64; fraternal twins showed correlation r = 0.41. However, when researchers examined only participants who reported high parental monitoring during adolescence, identical twins showed r = 0.52 and fraternal twins showed r = 0.38. What does the reduced identical-fraternal difference in the high-monitoring group suggest?
Parental monitoring constrains genetic expression of risk-taking by providing environmental structure that overrides genetic predisposition
Parental monitoring eliminates genetic influence on risk-taking because the identical-fraternal difference decreases
Genetic influence on risk-taking increases with parental monitoring because identical twins show lower correlation in the monitored group
Parental monitoring has no effect on the heredity-environment interaction because fraternal twins show similar correlation in both groups
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Answer: (A)
The identical-fraternal difference decreased from 0.23 (0.64 - 0.41) in the full sample to 0.14 (0.52 - 0.38) in the high-monitoring group. This smaller genetic effect under monitoring indicates that environmental structure reduces the proportion of risk-taking variation attributable to genetic factors. This demonstrates LO 1.1.A by showing heredity and environment interact: the same genetic predisposition produces different behavioral outcomes depending on environmental constraint, with monitoring reducing genetic expression.
Question 6
A family study examined empathy scores across biological relatives with varying degrees of genetic similarity and environmental contact. The data show: identical twins living together 0.68, identical twins living apart 0.61, fraternal twins living together 0.44, fraternal twins living apart 0.39, biological siblings living apart 0.35, adoptive siblings living together 0.22. What does the pattern of these correlations best illustrate about the heredity-environment interaction?
Both genetic similarity and shared environment contribute to empathy, with genetic factors showing stronger influence overall
Shared environment is the primary determinant of empathy because adoptive siblings show lower correlation than all biological relatives
Genetic factors determine empathy entirely because identical twins show the highest correlations regardless of living situation
Living apart eliminates environmental influence on empathy because separated twins show substantial correlations
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Answer: (A)
Identical twins living apart (0.61) exceed fraternal twins living together (0.44), demonstrating genetic similarity outweighs shared environment. However, identical twins living together (0.68) exceed identical twins living apart (0.61), showing shared environment adds to genetic influence. The pattern shows both factors matter, but genetic similarity produces larger differences. This demonstrates LO 1.1.A by showing heredity and environment interact: genetic predisposition provides the foundation while environment modulates expression.
Question 7
A study measured neuroticism correlations for 150 identical twin pairs raised together (r = 0.52) and 150 pairs raised apart (r = 0.48). What does the small difference indicate about neuroticism?
Genetic factors substantially influence neuroticism while shared environment contributes little.
Shared environment primarily determines neuroticism because groups show similar correlations.
Neuroticism is entirely genetic because identical twins correlate similarly across rearing.
Twins raised apart show higher correlation because separation increases gene activity.
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Answer: (A)
The near equal correlations indicate strong genetic influence and minimal shared environmental effect. If shared family environment mattered, twins raised together would be much more similar than those raised apart.
Question 8
A twin study tested reading ability in 200 identical and 200 fraternal twin pairs in the same school. For all children, identical r = 0.71 and fraternal r = 0.35. Among children with diagnosed dyslexia, identical r = 0.89 and fraternal r = 0.52. What does the larger identical-fraternal difference in the dyslexia group suggest?
Genetic factors play a stronger role in dyslexia than in typical reading.
Curriculum has no effect on reading because identical twin correlations are high.
Lower fraternal correlations reflect genetic dissimilarity, not greater dyslexia risk.
The bigger twin difference shows genetics are relatively more important in dyslexia.
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Answer: (A)
A larger identical-fraternal gap in the dyslexia group indicates stronger genetic influence. Identical r 0.89 versus fraternal r 0.52 shows higher heritability for dyslexia than for typical reading (0.71 versus 0.35).
Question 9
A family study measured conscientiousness across three generations: grandparent–parent r = 0.41, parent–child r = 0.38, grandparent–grandchild r = 0.18. What does the decline with genetic distance suggest about heredity and environment?
Both genes and direct parental environment influence conscientiousness across generations.
Conscientiousness is entirely genetic because correlations decline with genetic distance
Environmental factors are unimportant because grandparent–grandchild correlation is low
Declining correlations reflect reduced shared genes and less direct environmental exposure
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Answer: (A)
Both genetic inheritance and direct parental environment contribute to conscientiousness. Similar adjacent-generation correlations (0.41 and 0.38) despite reduced genetic sharing point to environmental transmission, while the lower grandparent–grandchild correlation reflects reduced genetic similarity and weaker direct exposure.
Question 10
A researcher measured heart rate, pupil diameter, and digestive enzyme secretion in participants during a timed math competition. Heart rate and pupil diameter increased significantly during the task, while digestive enzyme secretion decreased. Which nervous system division is primarily responsible for this pattern of physiological changes?
The sympathetic nervous system, which mobilizes resources for the stressful task by increasing arousal and redirecting energy away from digestion
The parasympathetic nervous system, which prepares the body for sustained mental effort by increasing heart rate and pupil dilation
The somatic nervous system, which controls the voluntary muscles needed to write answers and therefore increases all physiological arousal
The central nervous system, which directly controls all organ systems and produces these changes through direct neural pathways to the heart and digestive organs
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Answer: (A)
Recognizing the coordinated pattern of increased heart rate, dilated pupils, and decreased digestion reveals sympathetic activation during stress. The data shows the classic 'fight or flight' response where the sympathetic division prioritizes immediate action over maintenance functions, demonstrating understanding that the autonomic nervous system's divisions produce opposing effects on organ systems.
What's on the AP Psychology Unit 1 practice test
The standard version takes about 94 minutes and follows the timing and directions of the AP exam, sized to one unit:
- 20 Multiple Choice Questions (24 minutes)
- 1 FRQ – FRQ 1 – Article Analysis Question (AAQ) (35 minutes)
- 1 FRQ – FRQ 2 – Evidence Based Question (EBQ) (35 minutes)
Questions are drawn from 1544 multiple-choice questions and 36 FRQs written for Unit 1, Biological Bases of Behavior.
Practice AP Psychology Unit 1 FRQs
Answer the unit's free-response questions one at a time and get a score on every part.
- FRQ 1 – Article Analysis Question (AAQ) (16 questions)
- FRQ 2 – Evidence Based Question (EBQ) (20 questions)
Review Unit 1 before you start
- 1.1 Interaction of Heredity and Environment
- 1.2 Overview of the Nervous System
- 1.3 The Neuron and Neural Firing
- 1.4 The Brain
- 1.5 Sleep
- 1.6 Sensation