The U-Curve of Happiness is not Consistent Across Measures

The U-curve of happiness poses that happiness levels reach its peak levels in our younger years around age 20 and in our older years starting at around age 70, lowest amongst the middle years around ages 40-55. Studies debating the U-curve phenomenon of happiness have used different measures of happiness, however. In this study, we investigate the reliability of the U-curve phenomenon in a cross-sectional sample to replicate findings using each of the 17 different measures from previous studies. The aim was to identify measures that have similar and different outcomes with previously established results in a sample of 280 adults. Here we replicate the U-curve when different preregistered sets of control variables are included. We further show heterogeneity across happiness measures, showing that the U-curve is not consistent across items. Thus, care needs to be taken when interpreting the U-curve and the inconsistent evidence, as numerous studies using different, often self-made, items.