Why do individuals so willingly risk the enforcement of punishment of moral offenders? A satisfying explanation for moralistic punishment should consider possible incentives that could have reliably motivated individuals to incur the risks for punishment over the course of our evolution. Conceivably, moralistic punishment evolved to protect our social investments, namely individuals whose welfare was appraised to be beneficial to us in the future. In this chapter, we review empirical support for this reciprocity-based social capital theory, examining whether (1) third parties punish more on behalf of victims displaying signs of high value, and (2) whether individuals who systematically undervalue others’ welfare are actually less punitive. Finally, we present some implications of this punitive response for criminal punishment policy.