Background: Higher education institutions and universities aim to provide students with a range of transferable skills that enable them to become more thoughtful and effective employees, citizens, and consumers. One of these skills is critical thinking. Objective: The aim of the present research was to examine whether taking a psychology degree is concomitant with students' increase in critical thinking skills when students are not explicitly taught critical thinking. Method: Study 1 utilized a cross-sectional design and Study 2 a longitudinal design. The Watson and Glaser Critical Thinking Appraisal (WGCTA, UK) was used to measure critical thinking. Results: For both studies, the overall scores of WGCTA, as well as scores of the subtest of Recognition of Assumptions, were significantly higher for final-year than for first-year students. Conclusion: From the findings, we conclude that the levels of critical thinking by final-year psychology students may be enhanced. Teaching implications: We propose that teaching other aspects of critical thinking such as Evaluation of Arguments and Interpretation, as measured by this test, could be beneficial in further developing psychology students' overall critical thinking performance.