Supportive attitudes towards intimate partner violence against women (IPVAW) normalize and promote these aggressive behaviors. As a result, more and more research is proposing the identification, analysis and intervention of these attitudes. However, the vast majority of this research focuses on students. The main objective of this paper is to analyze these supportive attitudes throughout the lifecycle. An opportunity sample of 200 Spanish participants, by age and sex fixed quotas, took part in this study. Attitudes were measured using the Inventory of Distorted Thoughts about Women and Violence, the Inventory of Beliefs about Intimate Partner Violence and the Gender Violence Implicit Association Test, a personalized form of Implicit Association Test (IAT). The results show that explicitly measured supportive attitudes towards intimate partner violence against women differ between age groups, adopting a U-shape distribution: lower acceptance among middle-aged-adults and young-adults and higher acceptance among adolescents and older adults. However, when these attitudes were implicitly measured, the IPVAW rejection increased with age, which is a counter-intuitive result and inconsistent with previous theoretical evidence. In summary, these results support an age effect that differs according to the measure of attitudes used and highlight some difficulties related to based-on-reaction-time measures among older people. This suggests the need for further research on the topic, especially among the older population.