Is it more efficient to vote in our own interests or in the interests of the society? Prima facie, this seems to be a useless question with an obvious answer.
I approach the question using the framework of efficiency; that is, the extent to which preferences are satisfied by the allocation of limited resources.
It is almost certain that we are much more privy to our own preferences than the preferences of others, much less that of society as a whole. Thus, if the sole metric was to be the maximization of our preferences, it is clearly more desirable for the resources to be allocated with our own hands. After all, nobody ought to know our needs and wants better than ourselves.
If we acknowledge that our intuitions on our preferences are more accurate, and if we were to consider voting as a means to most accurately determine the preferences of society, then it follows that voting is more accurate if everyone were to vote in their own interests, rather than in their guesstimates of what the common interest is. By adopting the pretense of voting in society's interest, there is a risk of converging on something which is merely a fiction, a perceived preference instead of an actual one.