The concept of 'nudge theory,' popularized by Richard Thaler and Cass Sunstein, posits that subtle changes in the way choices are presented can significantly influence human behavior without restricting freedom of choice. This approach has been widely adopted in public policy, particularly in areas like organ donation, where default options are structured to increase participation rates. However, critics argue that nudges can be manipulative, as they exploit cognitive biases that individuals may not consciously recognize. Moreover, the effectiveness of nudges is often context-dependent, varying across cultures and demographic groups. A recent meta-analysis of 126 studies found that while nudges generally produce positive effects, their magnitude is smaller than initially claimed, and publication bias may overstate their success. Thus, while nudge theory offers a cost-effective tool for behavioral change, its application requires careful ethical consideration and empirical validation.