Globally aging populations raise worldwide concerns about how an older population will be valued. Cross-culturally, many espouse that Eastern cultures revere their older adults more than Westerners, due to stronger collectivism and filial piety traditions. In contrast, this paper proposes a resource tension hypothesis, whereby rapid population aging causes pragmatic strain across all modernized societies, fostering ageism. Three studies supported this resource tension hypothesis, focusing on the pragmatic role of public pensions-a fundamental resource inherently pitting older versus younger generations-in fostering ageism. Study 1 tested the relationship between nation-level public pension rate and attitudes toward older adults by using World Values Survey and European Social Survey data sets. Study 2 further explored this relationship via priming both the pension-based resource scarcity and the intergenerational competition over the public pension. Study 3 offered an intervention-future-self-thinking via a photo ager-on reducing intergenerational tensions under pension scarcity conditions. Study 1 found a significant link between nation-level public pension rate and negative older adult attitudes across 39,700 World Values Survey, and 29,797 European Social Survey data points. Study 2 further supported the pension-ageism link via experimental methods. Participants who were reminded of the scarcity of pensions and intergenerational competition exhibited more negative attitudes toward older adults. Study 3 confirmed the effect of the future-self intervention on enhancing attitudes toward older adults even despite scarce pension resources. The findings support a resource explanation in driving perceptions of older adults, implicate pensions as a key mechanism driving intergenerational attitudes, and identify future-self thinking as a critical intervention. The present studies open up new research pathways for understanding and accommodating the globally aging population.