Have you seen Bond & Lang 2018? Their abstract:
We replicate nine key results from the happiness literature: the Easterlin Paradox, the ‘U-shaped’ relation between happiness and age, the happiness trade-off between inflation and unemployment, cross-country comparisons of happiness, the impact of the Moving to Opportunity program on happiness, the impact of marriage and children on happiness, the ‘paradox’ of declining female happiness, and the effect of disability on happiness. We show that none of the findings can be obtained relying only on nonparametric identification. The findings in the literature are highly dependent on one’s beliefs about the underlying distribution of happiness in society, or the social welfare function one chooses to adopt. Furthermore, any conclusions reached from these parametric approaches rely on the assumption that all individuals report their happiness in the same way. When the data permit, we test for equal reporting functions, conditional on the existence of a common cardinalization from the normal family. We reject this assumption in all cases in which we test it.
The paper seems extremely relevant to section 4.
Also, in contrast to your experience in trying to think of happiness nonlinearly, I find it quite easy to do. Intuitively, the difference between 1 (maximal unhappiness) and 2 is much bigger than between 2 and 3. Same for 8 vs 9 and 9 vs 10.
Thanks. I agree with you that it does not show complete untrustworthiness. Adjusted the language a little bit.