Blood donations as costly signals of donor quality

Abstract

This is the first empirical investigation of blood donations in evolutionary perspective. We examine blood donor and non-donor attitudes about health and injury risks, donor characteristics, and the social value of donor participation. We propose that blood donations may communicate qualities about donors to third parties. Observers may benefit from information about the donor's health, value as a reciprocal partner, and/or ability to endure what is perceived as an anxiety-provoking and risky experience. Donors may benefit from an enhanced reputation, which can lead to greater access to cooperative networks and high-quality partners. We found that participants recognized the need for blood and perceived blood donors as generous and healthy. Study results indicated that anxiety and the perceived risk of a negative health consequence dramatically affected the willingness of donors and non-donors to donate blood in the future. These findings support our hypothesis that the act of blood donation may signal adaptive information about donor quality to third parties.