The following quote is misattributed to Ahuvia, (2002)

This research also supports the broaden-and-build theory of positive emotions by demonstrating that higher levels of happiness may expand an individual’s mindset to include thoughts of others.

The quote comes from Aknin, Dunn, & Norton, (2011a), p. 352.

Also, this post has been absurdly useful to me. Fantastic job! :)