The first phase of a study investigating textbook readability and students' reading levels used three traditional formulas to assess the readability levels of 51 primary textbooks from college introductory social science courses in 7 disciplines. The second phase investigated the relationship between the readability levels of students' texts, students' reading levels and study habits, and their final grades. The three-formula readability analysis indicated that, on the average, the 51 social science texts were written at the low-to-mid college level. The Fog Index yielded consistently higher results than the Fry and SMOG formulas. The main reading level was 15.1, with 80% of the students placing at or above the college level and 40% scoring at the top of the reading level scale. Students generally showed a high number of strengths in study habits, which was partly attributed to their having received instruction in how to study. When reading levels were categorized, an overall positive relationship was revealed between reading levels and final grades. No discernible relationship was found between study habits and final grades. (HOD)