On income/happiness:

"It’s a little easier to see why people would pass along the wrong story here, since it’s easy to misinterpret the data when it’s plotted against a linear scale, but it’s still pretty easy to see what’s going on by taking a peek at the actual studies."

Googling

http://wws.princeton.edu/news-and-events/news/item/two-wws-p...

"People’s life evaluations rise steadily with income, but the reported quality of emotional daily experience levels off at a certain income level, according to a new study by two Princeton University professors [...]"

So seemingly that has nothing to do with the scale used, but with the definition of happiness. Guess someone didn't look "at the actual study"?