The set point theory
According to this theory,the individual propensity to happiness is a personal trait of largely genetic origin and influenced by personality.The explanation for the stagnation of happiness is that happiness is a stochastic phenomenon.Chance distributes unequal amounts of happiness among people’s genetic codes ,leaving the average level unchanged.
The decreasing marginal utility of money. This idea- that of a progressive saturation of needs,or at least of those needs that can be satisified by marketable goods-is general and is consistent with a variety of approaches,including mainstrain growth theory.It may wvoke an image of societies that are affluent and stated with regard to material needs,but in which individuals can not buy what they truly need.This idea is compatible with a broad variety of critiques of materialism and consumerism and also with a large body of studies.mainly psychological,which emphasize the primarly importance of the quality of the relational world in which individuals live in determining their happiness.and it is further more consistent with several other explanation furnished by pshcologists and sociologists.
Adaptation
An increase in income has only temporary effects on people’s happiness because they progressively adapt to the new circumstances.This theory is often presented as the flip side of coin of one of the keys of human evooluntionary success,the elevated capacity to adapt.that which saves up from sinking into despair in the face of adversity also prevents us from elevating ourselves to a more stable,higher plane of experience under favorable circumstances.Adapation theory is some times presented in conjunction with set point theory:the effects of external circumstances on happiness are temporary and its long-term level is determined by biology and personality.However,these two the