It seems to me that this study says very little about the effects of superfluous apologies and more about the social etiquette of greeting someone before you as

It seems to me that this study says very little about the effects of superfluous apologies and more about the social etiquette of greeting someone before you ask for a favor. The study's confederate could have said "Good morning," "Hello there" -- anything other than simply making a request -- and achieved a better response rate.