From the perspective of survival adaption, adverse childhood experiences may promote creativity, and this effect would be enhanced by external threat. This study adopted three approaches to explore the impact of childhood harshness and unpredictability on creativity. By using a historiometric approach to investigate the adverse childhood experiences among eminent psychologists in 20tth century, Study 1 found that the proportion experiencing childhood adversity was significantly higher than the proportion who did not, especially in the group experiencing an external threat. Study 2 measured college students' early childhood experiences and creative thinking in a threatening circumstance (COVID-19 pandemic), which showed that childhood harshness was significantly correlated with the originality of creative thinking. Study 3 explored the moderating role of threat through experimental manipulation. Results showed that childhood harshness predicted originality only in the threatening condition but not in the control condition. These results have theoretical significance for understanding individual creative development.