Adapting training methods to specific teacher traits to best facilitate the training effects for preservice teachers is an important, yet neglected, topic in aptitude-treatment interaction research. This study investigated interactions between four personal traits (CT-dispositions, thinking styles, CT-skills, and intrapersonal intelligence) and two designed treatments on preservice teachers’ behavior change during a computer-simulated teaching experience. One hundred and seventy-eight preservice teachers participated in this study. The CS-TGCTS simulation program was employed to measure the preservice teachers’ actual use of effective teacher behaviors, as well as the four targeted personal traits which were measured by three Likert-scale inventories and one multiple-choice test. The results suggest that preservice teachers with high levels of CT-dispositions, CT-skills, and intrapersonal intelligence – as well as those with judicial or legislative thinking styles – are mindful, analytical, and reflective in their teaching practices and therefore more likely to continually improve their teaching skills.