What did the Ein-Dor & Hirschberger (2012) study involve?

• A. One hundred couples participated in a lab experiment.
• B. 75 heterosexual couples completed a sex diary for 18 days.
• C. 50 couples watched romantic movies.
• D. Survey of college students.

Answer: (B)

Longitudinal diary data from couples captures how sexual activity and related feelings unfold across days, giving ecologically valid insight into daily dynamics. Ein-Dor and Hirschberger used 75 heterosexual couples who kept a sex diary for 18 days, which directly matches this approach. Diary studies let researchers examine how partners’ experiences influence each other over time and across events in daily life, rather than relying on a single lab session or retrospective recall. The other options describe designs that don’t provide the same day-to-day dyadic diary data (a lab experiment, watching romantic films, or surveying college students), so they don’t fit the described study as well.