First tests of Euclidean preference integration in friendship: Euclidean friend value and power of choice on the friend market

Abstract

Close friendships are associated with greater happiness and improved health; historically, they would likely have provided beneficial fitness outcomes. Yet each friendship requires one's finite time and resources to develop and maintain. Because people can maintain only so many close relationships, including friendships, at any one time, choosing which prospective friends to pursue and invest in is likely to have been a recurrent adaptive problem. Moreover, not all friends are created equal; some might be kind but unintelligent, some intelligent but disloyal, and so on. How might people integrate their friend preferences to make friend choices? Work using a Euclidean model of mate preferences has had significant success in elucidating this integration challenge in the domain of mating. Here, we apply this model to the domain of friendship, specifically exploring same-sex best and close friendships. We test and find some support for several critical predictions derived from a Euclidean integration hypothesis: People with higher Euclidean friend value (a) have best friends who better fulfill their best friend preferences, (b) have higher friend-value ideal best friends, and (c) have higher friend-value actual best friends. We also (d) replicate existing similar findings with regard to mating and (e) additionally provide a first test of whether people's Euclidean friend value (versus mate value) is a better predictor of their friend outcomes, and vice versa, finding some, albeit mixed, support for the dissocialbility of these constructs.