This research investigates the changes in English as a Foreign Language (EFL) learners' psychological attributes in relation to awareness of the lexicogrammatical features and generic structures of a discussion genre essay. This was achieved by implementing a genre-based approach to text-based writing lessons during a 15-week course. The following lesson procedure was implemented: stage (1): modeling and deconstruction of a text, stage (2): writing of target texts, stage (3): genre analysis of peers' essays, and stage (4): writing of an analysis reflection. The results indicated specific improvements in genre-based writing, particularly among low-proficiency English learners. Results suggest that their understanding of "interpersonal meaning" such as modal verbs improved. Improvements in the use of modal auxiliaries were also noted, in that the word "should" did not appear in pre-writing texts; however, the frequency improved in post-writing texts, especially in the final paragraph, which comprised the writers' opinions and suggestions.