Relative vs Absolute Wealth and Revealed Preference
Economists prefer to measure preference by actions rather than words. It occurred to me that we have such evidence for this question. Lots of people choose to migrate from one society to another. If you go from a rich society to a poor society you are likely to substantially increase your relative position, since you will bring with you both wealth and human capital that are high compared to the average in your new home. If you go from a poor society to a rich society, the opposite can be expected.
I don't have data, but my impression is that migration from a poorer to a richer society is much more common than migration the other way. If so, that provides evidence, at least for the alternatives that migrants face, that absolute wealth is more important than relative wealth.