Abstract
The paper explores the factorial relationship between measures of critical thinking skills, non-verbal intelligence, and academic performance (A-levels and undergraduate degree marks). One hundred and twenty-nine undergraduate psychology students (94 first years and 35 third years) participated by completing two subscales of the California Critical Thinking Skills Test (CCTST) and Raven's Advanced Progressive Matrices Set 1 (APM-S1); they also provided information on their A-level points and degree marks. An exploratory factor analysis grouped the CCTST subscales of evaluation and inference with the APM-S1. The resultant factor was named 'Reasoning skills', and the A-levels and degree marks formed a second factor named 'Academic knowledge'. Furthermore, third years scored significantly higher than first years on the CCTST evaluation subscale (effect size d = 0.56), and there was a moderate effect size difference between their CCTST inference subscale scores (effect size d = 0.31) but only small effect size differences between the two groups on academic performance (d = 0.16) and APM-S1 scores (d = 0.04). It was provisionally concluded that critical thinking changes over the course of a degree and that these abilities are not well captured by traditional academic assessments. The implications of this for teaching and learning in higher education are briefly considered.