Under the influence of Darwin's theory of biological evolution, instinct gradually became a core issue in the fields of human and animal psychology in the late 19 th and early 20 th centuries, soon to be relegated to the realm of "magic." At the height of its popularity, theorists interpreted almost all human behavior in relation to instinct. A young Chinese developmental psychobiologist, Zing-yang Kuo, adopted John B. Watson's approach to behaviorism, strongly advocating for the complete removal of instinct from the interpretation of human and animal behaviors-an approach that started a massive anti-instinct movement in the field of psychology in the United States. After returning to China, Kuo continued to spread his knowledge of radical behaviorism among the intellectual elite, promoting the debate on instinct, "one of the three biggest debates in the history of modern Chinese psychology." Kuo's suggestion that the origin of behavioral development could be traced in a laboratory setting was scorned by conservative US researchers. Convinced that he could resolve the controversy surrounding instinct in the laboratory, and following critical reflection on the matter, Kuo performed a range of experiments in China to verify his anti-instinct claims. Ultimately viewed as the most important development in the Chinese anti-instinct movement, Kuo's work bridged the gaps in global debates on instinct. Psychologists such as Wei Joseph Ai, Shuh Pan, and Juefu Gao all joined the movement, and it also attracted the interests of other public intellectuals, including Jianren Zhou and Shicen Li. Centered on topics such as the existence of instinct, its definition, whether instincts are inherited, and the relationship between instincts, heredity, and environment, the heated discussion in China's intellectual community surfaced positive, negative, and mixed reactions. While the Chinese anti-instinct movement did not develop extensive theories, there is no doubt that, as a natural extension of the international anti-instinct movement, it responded to the main contentions of the debate. While the Chinese movement expedited the methodological transmission of the psychological study of instinct from armchair to laboratory, it also confused the interpretation of development with that of evolution.