Depends how you define standard of living. If we consider "standard of living" to mean "happiness", as you seem to imply, that actually correlates well with real (inflation/CPI-adjusted) income. Accordingly, happiness levels have been flat and/or declining for the vast majority of the population [1], just as real wages have.

[1]: http://ideas.repec.org/p/nbr/nberwo/7487.html