["Kyklos, Volume 79, Issue 2, Page 338-356, May 2026. ", "\nABSTRACT\nThis study investigates the influence of a CEO's firstborn son on corporate investment, taking into account the contingent role of the CEO's birth after the Cultural Revolution and the number of sons. Using a unique data set of the top 500 richest individuals and their associated corporate investments on the Shanghai, Shenzhen, and Hong Kong stock exchanges between 2008 and 2020, our findings demonstrate that a CEO's firstborn son has a significant positive impact on corporate investment. Moreover, the number of sons and the CEO's birth after the Cultural Revolution have opposite moderating effects on this relationship. This finding adds new insights for corporate investment from the behavior finance perspective and guides firms' investment efficiency improvement.\n"]