**7. Discussion**

#### **7.1 Why the difference between theories that hold happiness immutable?**

These data clearly contradict theories that imply that average happiness in nations will hardly change over time**.** Though there is considerable stability, there is undeniable change.

These theories have been advanced for some reason. One reason seems to be that they were proposed around 1980, when the available data showed little change in happiness over time, neither in individual follow-up studies nor in trends of average happiness in nations.

The first sizable time series at the nation level was from the United States and Japan, in which average happiness did not change until today. In retrospect, these are exceptions to the rule that average happiness does change over time and that this change is related to economic growth [22].

Another reason, specific to the Easterlin paradox, is what might be called the 'cognitive fallacy', seeing happiness as mere contentment while ignoring its affective component (cf. Section 2.1). The current distinction between life *satisfaction* (overall happiness) and life *evaluation* (cognitive component) was not made at that time. Mere contentment is indeed likely to depend on social comparison.

Trait theory was inspired by the stability of individual happiness observed in the first follow-up studies in developed nations. Change over the life time became visible only when longer time series became available [23].

The variant of trait theory proposed by Cummins [5] does acknowledge the affective component of happiness, but its assumption of homeostatic defense of a set-point mood level around 7.5 does not fit data that became available later, such as the dip of happiness during the COVID-19 pandemic that hit not only the least happy, prone to homeostatic failure, but also the happiest people (cf. Section 5.4).

#### **7.2 How does liveability theory account for stability and change in happiness?**

The initially observed stability of happiness can also be explained by the liveability theory. Need gratification will remain at the same level when positive and negative changes in living conditions balance out or when deteriorations in external living conditions are compensated by improved life-ability. From this perspective, it is explicable that after the fall of communism in 1990, average happiness in Eastern Europe followed a V-pattern; in the first 10 years a decline and since 2000 a sharp increase [24]. The regime change involved a temporary deterioration of external living conditions, for example, a catastrophic decline in the material standard of living which hit pensioners in particular, and lasted for several years [25]. Required abilities for dealing with the new market economy had not been developed under communism and their acquirement also took time.

#### **7.3 Why more change for the better?**

Average happiness in nations did not only change considerably during the last decade (total change) but it changed also more for the better (net change). This rise in happiness went together with an unprecedented rise in longevity. All nations were subject to the ongoing process of societal modernization in the period considered, and average happiness was already much higher in the most modern nations of our

time [26]. All this supports the theory that human nature, as developed in the conditions of hunter-gatherer existence, fits better with modern industrial society than with traditional agrarian society [27].

### **7.4 Robustness**

The above conclusions draw on 200 time series on average happiness in 50 nations. Though this is more than ever reported before, we cannot exclude the possibility that a different pattern could have been found if all nations of the world had been considered. Likewise, the conclusions could be specific to the questions on happiness used and the periods for which data were available. Though possible, we do not deem that probable, among other things because average happiness appeared to be equally changeable in all kinds of nations, in all kinds of time series and in all periods. Moreover, we do not need more evidence to show that average happiness in nations *can* change over time.
