Recent research has verified that many once-deemed construct irrelevant individual differences (IDs) including cognitive and affective factors do potentially affect second or foreign language (L2) achievement rate and route, and efforts are made to maximally identify such factors and figure out the interplay models of second language achievement and such factors. The present mixed-methods study followed the same objective and explored the model of interactions among L2 grit, willingness to communicate (WTC), foreign language enjoyment (FLE), and L2 achievement of Iranian English as a foreign language (EFL) learners. The quantitative phase of study surveyed 208 Iranian EFL learners’ L2 grit, FLE, and WTC. IELTS or TOEFL scores were also gathered as a measure of the participants’ L2 achievement rate. Multiple linear regression analysis was performed on the obtained data to figure out the predictability of L2 achievement by the given variables. The analyses verified that all three variables were strong predictors of L2 achievement, with FLE being the strongest predictor. Moreover, structural equation modeling (SEM) approach indicated that bidirectional relations exist between FLE and WTC, FLE and L2 grit, L2 grit and WTC, as well as directional relations between L2 grit and L2 achievement, WTC and L2 achievement. Furthermore, as for the qualitative phase of study, the data obtained from the semi-structured interviews of around 10 percent of the respondents were qualitatively analyzed and interpreted in light of the results gained from the quantitative phase. The overall findings verified that L2 grit, FLE, and WTC were all related to L2 achievement and the hypothetical model of interactions was rendered into a statistically valid and logical model of interplays among the factors. An implication of the study findings is that foreign or second language education needs to recognize the determining direct impact of positive psychology variables including enjoyment on the learning process. 

Mohammad Ahmadi Safa is a faculty member at Bu-Ali Sina University, Iran, specializing in language assessment, second-language learning, and sociocultural theory. He has published widely on dynamic assessment, exam washback, and intercultural communicative competence.