Language learning failure is often directly related to demotivation. The purpose of this study is to examine the process of demotivation and identify its sources within four years of an undergraduate degree programme. To this end, based on the complex dynamic systems perspective of the dynamic systems theories (DSTs), the demotivation test battery was developed and administered to 308 English major students. The results identified three salient demotivating constructs: (1) Institution related, (2) Significant others related and (3) Self-related, from among which the Institution related was the most influential and progressive through years. While MANOVA results confirmed the same pattern, it revealed stronger impact for the 3rd- and 4th-year students. In sum, the present findings provide support for the DSTs and indicate that the wider social context and prevailing discourses of the society are in constant interaction with the functions and attitudes of the others existing within that context.