We investigate the impact of self-construal on extreme responding in six studies. The results show that people with an independent self-construal generally answer more extremely to survey items than those with an interdependent self-construal, especially when the items are self-relevant (Studies 1a and 1b) and when these items are fluently processed (Study 3). Using an experimental causal chain design, this research also demonstrates that self-concept clarity drives the effect of self-construal on extreme responding. In particular, people with an independent self-construal have a higher level of self-concept clarity (Study 2a), and self-clarity leads to an extreme response style (Study 2b). In Study 4, we demonstrate that the difference in extreme responding can partly explain a well-established self-construal effect, and we offer a solution to control for the bias in extreme responding in self-construal research.