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.