Research Design (DP IB Psychology: HL): Exam Questions

Explain one way in which the design of your class practical aimed to increase validity.

Discuss the following study with reference to two or more of the following concepts: bias, causality, measurement, and/or responsibility.

Hunt, Eastwick and Finkel (2015) conducted a quantitative, correlational study to investigate how how long couples knew each other before dating affects physical attractiveness matching in romantic relationships. The study involved 167 heterosexual couples in the United States, including both dating and married couples. Each partner’s physical attractiveness was rated by independent observers using video recordings, and the researchers recorded how long each couple had known each other before becoming romantically involved.

The results showed that couples who started dating soon after meeting were more similar in physical attractiveness, whereas couples who had known each other for longer before dating were more likely to differ in attractiveness. This suggests that when people know each other for longer, non-physical factors such as personality and compatibility become more important, reducing the role of physical appearance in partner choice.

References: Hunt, L. L., Eastwick, P. W., & Finkel, E. J. (2015). Levelling the playing field: Longer acquaintance predicts reduced assortative mating on attractiveness. Psychological Science, 26 (11), 1759–1772

Discuss the following study with reference to two or more of the following concepts: bias, causality, measurement, and/or change.

Noble et al. (2022) conducted a true experiment to test whether alleviating poverty can influence infant brain development. Over 1,000 low-income mothers in the United States were randomly assigned to receive either a high monthly cash gift ($333) or a low cash gift ($20) from the birth of their child.

After one year, infants in the high-cash group showed significantly more high-frequency (“fast”) brain activity, as measured by EEG, than those in the low-cash group. Such fast brain waves are associated with more advanced cognitive development, suggesting that the income boost had a positive causal effect on the babies’ brain development.

References: Noble, K. G., Magnuson, K., Gennetian, L. A., Duncan, G. J., Yoshikawa, H., Fox, N. A., Halpern-Meekin, S., Hyde, L. W., Ivory, J. J., & Ziol-Guest, K. M. (2022). Baby’s first years: Design of a randomized controlled trial of poverty reduction in the United States. Developmental Cognitive Neuroscience, 53, 101044.

Discuss the following study with reference to two or more of the following concepts: bias, causality, measurement, and/or change.

James et al. (2015) investigated whether playing Tetris after reactivating a traumatic memory could reduce intrusive memories. 72 participants watched a distressing 12-minute film of real-life accidents to simulate exposure to a traumatic event. 24 hours later, they were randomly assigned to four conditions: memory reactivation plus Tetris, reactivation only, Tetris only, or no task. Reactivation involved viewing still images from the film to trigger recall of the traumatic scenes. This triggers a process called reconsolidation — a brief window during which the memory becomes unstable and open to change. After a 10-minute break, participants then played Tetris for 12 minutes.

Intrusive memories were recorded in a daily diary over 7 days. Only the reactivation-plus-Tetris group experienced significantly fewer intrusions, with intrusions in this group declining rapidly to almost zero by Day 2. This suggests both components are necessary — the memory must first be reactivated, opening this window of instability, before a visuospatial task competing for the same working memory resources can disrupt it.

References: James, E. L., Bonsall, M. B., Hoppitt, L., Tunbridge, E. M., Geddes, J. R., Milton, A. L. & Holmes, E. A. (2015). Computer game play reduces intrusive memories of experimental trauma via reconsolidation-update mechanisms. Psychological Science, 26(8), 1201–1215

Discuss the following study with reference to two or more of the following concepts: causality, bias, perspective, and/or responsibility.

Haun & Tomasello (2011) investigated whether preschool children conform to the incorrect judgements of their peers. 72 children aged 4, drawn from kindergarten classes in Leipzig, Germany, were organised into groups of 4 and given seemingly identical picture books. However, one child (the focal child) in each group secretly received a different version, meaning their correct answer differed from the other 3. The focal child always answered last.

In the public condition, children answered aloud; in the private condition, they pointed silently, hidden from others. Results showed that 12 out of 18 focal children conformed at least once in the public condition compared to 8 out of 18 in the private condition, with overall conformity rates of 37.5% (public) and 19% (private). The researchers concluded that children as young as 4 distinguish between public compliance and private acceptance.

References: Haun, D. B. M. & Tomasello, M. (2011). Conformity to peer pressure in preschool children. Child Development, 82(6), 1759–1767

Discuss the following study with reference to two or more of the following concepts: measurement, causality, bias, and/or perspective.

Kraft & Pressman (2012) investigated whether manipulating facial expressions influences physiological stress responses. 170 university students, naive to the true purpose of the study, held chopsticks in their mouths to produce either a Duchenne smile (engaging mouth and eye muscles), a standard smile (mouth only), or a neutral expression. Critically, half the participants in each smiling group were explicitly asked to smile, while the other half received no smiling instructions and were unaware their chopstick position produced a smile. Participants then completed stressful tasks including tracing a mirror-reflected star and submerging a hand in ice water while heart rate was monitored continuously.

Results showed that all smiling participants, including those unaware they were smiling, had significantly lower heart rates during stress recovery compared to the neutral group. The researchers concluded that the physical act of smiling can reduce physiological stress responses even without conscious awareness.

References: Kraft, T. L. & Pressman, S. D. (2012). Grin and bear it: the influence of manipulated facial expression on the stress response. Psychological Science, 23(11), 1372–1378

Discuss the following study with reference to two or more of the following concepts: causality, measurement, change, and/or responsibility.

Troller-Renfree et al. (2022) investigated whether unconditional cash transfers to low-income mothers affect infant brain development. As part of the Baby's First Years project, 435 mothers from four US cities were randomly assigned shortly after giving birth to receive either $333 per month (high-cash group) or $20 per month (low-cash control). The transfers were unconditional. When infants were approximately one year old, brain electrical activity was recorded using a portable EEG system in the family home.

Results showed that infants in the high-cash group displayed significantly more high-frequency brain activity, which previous research has associated with cognitive development and learning, compared to the low-cash group. The researchers concluded that reducing poverty directly impacts early brain development.

References: Troller-Renfree, S. V., Costanzo, M. A., Duncan, G. J., Magnuson, K., Gennetian, L. A., Yoshikawa, H., Halpern-Meekin, S., Fox, N. A. & Noble, K. G. (2022). The impact of a poverty reduction intervention on infant brain activity. Proceedings of the National Academy of Sciences, 119(5), e2115649119

Discuss the following study with reference to two or more of the following concepts: measurement, causality, bias, and/or change.

Ward et al. (2017) conducted an experiment to investigate whether the mere presence of a smartphone reduces available cognitive capacity. Nearly 800 university students completed cognitive tasks measuring working memory (an operation span task, where participants solve maths problems while remembering words) and attention (a go/no-go task, where participants press a button for some signals but not others). Before the tasks, participants were randomly assigned to place their smartphone in one of three locations: face down on the desk, in a pocket or bag, or in another room. All phones were silenced.

Participants who had their phone in another room performed best on both tasks. Those with their phone on the desk performed worst. The effect was strongest for participants who reported being highly dependent on their smartphones. The researchers concluded that the mere presence of a smartphone reduces cognitive capacity, even when participants are not actively using it.

References: Ward, A. F., Duke, K., Gneezy, A. & Bos, M. W. (2017). Brain drain: The mere presence of one's own smartphone reduces available cognitive capacity. Journal of the Association for Consumer Research, 2(2), 140–154

Discuss the following study with reference to two or more of the following concepts: bias, measurement, change, and/or perspective.

Asscheman et al. (2020) investigated how children's sharing behaviour develops between the ages of 8 and 12. A total of 1,108 Dutch schoolchildren were followed across grades 2 to 6 of elementary school. Each year children played a sharing game in which they were given 10 stickers and asked how many they would like to share in three separate conditions: with an anonymous peer, with their best friend, and with a classmate they disliked. Researchers also measured each child's likeability in the classroom using peer ratings.

Results showed that girls shared more stickers than boys across all conditions. Children shared more with their best friends than with strangers or disliked classmates. Children who were liked by their classmates shared more overall, while disliked children shared less with everyone. Sharing with strangers and disliked peers remained stable across grades, while sharing with best friends decreased slightly over time.

References: Asscheman, J. S., He, J., Koot, S., Buil, J. M., Krabbendam, L. & van Lier, P. A. C. (2020). Classroom peer preferences and the development of sharing behavior with friends and others. International Journal of Behavioral Development, 44(5), 412–423

Discuss the following study with reference to two or more of the following concepts: measurement, causality, bias, and/or perspective.

Park (2025) conducted an experiment to investigate whether expressing gratitude digitally, compared to privately, influences well-being and prosocial intentions (willingness to help others). 706 adults in the United States were recruited online and randomly assigned to one of four conditions in a 2 x 2 design. Participants were first asked to write about either (a) a recent experience they felt grateful for, or (b) a recent hassle or annoyance. They were then assigned to share their reflection either in a private, non-digital way (writing only for themselves) or in a public, digital way (writing in a shareable social media-style format). After writing, participants completed questionnaires measuring well-being (happiness and life satisfaction) and prosocial intentions (willingness to help others and volunteer).

Results showed that gratitude reflections improved well-being more than hassle reflections. Sharing gratitude publicly increased prosocial intentions more than sharing privately, while expression mode had less effect in the hassle condition.

References: Park, J. (2025). Gratitude in the digital age: The effects of experience type and expression mode on well-being and prosocial intentions. SAGE Open, 15(1), 21582440251385690