We appreciate the lively and wide-ranging discussion of our exposition of selective investment theory (SIT). Commentators raised many excellent points, both positive and negative. In structuring our reply we summarize features of SIT seen as strengths and weaknesses by the commentators, and then turn our attention to critiques that are troubling to us, as they appear to be based on a misreading or mischaracterization of SIT. In conclusion, we consider the possibilities and obstacles involved in any attempt to recast the functional significance of social relationships.