simple life
Will having more wealth actually make you happier? According to a number of studies an addition to your income isn't only unlikely to make you happier, but it can make those around you less happy, and you for the fear of losing it.

To explain, we must first look at a study from the National Bureau of Economic Research. Two economists, David Blanchflower of Dartmouth and Andrew Oswald of Warwick, set out to document the relation that age has to overall happiness. What they found was that as income tends to increase steadily over time, happiness follows a U-shape pattern, dipping to its lowest point at around age 45, then quickly climbing up thereafter.

A large-scale survey from the General Social Survey, which included around 20,000 men and 25,000 women of 16 years and older supports these findings. After asking Americans to rank their happiness on a 3 point scale ranging from "very happy" to "pretty happy" to "not too happy", they found a resulting average of 2.2, or just over "pretty happy". The Eurobaromoter, after conducting a similar survey on close to 400,000 men and women in 11 European countries from 1975 to 1998 found that the average self-assessed happiness score across Europe is 3 out of 4.

After further investigation, Oswald and Blanchflower found that the age of any given person in the developing world is more powerful in determining overall happiness than a halving or doubling of income. Also, they found that people of every gender and income have become enormously less happy throughout the past century. The difference in levels of happiness between those born in the 1960's vs the 1920's is the same effect as a tenfold difference in income, despite the fact that the younger generation is far more prosperous.
"I thought, if I could make 10 million dollars then it must be too easy. In fact, I honestly thought, everyone else had probably already made 11 million dollars. So then I felt poor again. I now needed 100 million dollars to be happy." ~James Altucher
What could explain this sharp decrease in happiness over time? Well, one of the largest societal changes that occurred throughout the 20th century was the onset of a mass consumerist culture. Before the roaring 1920's, life was much simpler and people didn't have strong desires for material things beyond the basics to live a fulfilling life like we do today.

On a scientific level, the ultimate reward for the purchase of a new watch, car, or other status symbol is a short-term release in dopamine which triggers a brief period of personal satisfaction. This is why we feel good after buying new things and it's where the term "retail therapy" comes from. However, the happiness one gets from material worth is short-lived. After time, the buyer will revert back to their original demeanor, while obtaining a sense of comfort and security from those new things they bought.

From this perspective, it begins to make sense why prosperous people in the developing world are some of the most prone to depression; they become afraid of losing what they have which their peers don't. In fact, those on the opposite end are shown to have the reverse effect and often become more depressed when around those with greater wealth. Contrary to popular belief that areas of high poverty produce higher homicide rates, it is actually those with the highest income disparity.
"Riches leave a man always as much and sometimes more exposed than before to anxiety, to fear and to sorrow." ~Adam Smith