Classifying and explaining the causal and functional relationship between age and life satisfaction, especially in an international context, is still a major open question in demographics and happiness-research. Especially the debate whether to include sociodemographic control variables in these models has received much attention and deserves more discussion. The current contribution takes a cross-country perspective and attempts to sort countries into larger clusters, depending on their specific functional form. Using cross-sectional data from 81 countries with more than 170,000 respondents, the analyses demonstrate that there exist three larger clusters which display distinct functional relations (linear decline, U-shape, decline with a stable old-age period). Sociodemographic controls are not introduced since the total causal effect is to be estimated. Furthermore, the contribution explains cluster membership exploratively using macro indicators. While it becomes clear that countries with a linear decline are usually less developed countries, differences between the other two clusters are much less obvious.