https://doi.org/10.1177/0146167217739262 Personality and Social Psychology Bulletin 1–13 © 2017 by the Society for Personality and Social Psychology, Inc Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0146167217739262 pspb.sagepub.com Empirical Research Paper Mate selection is central to reproduction, the driving engine of biological evolution. This fact has motivated much research on human mate preferences, revealing universal preferences for kindness, intelligence, age, beauty, status, resources, health, and more (Buss, 1989; DeBruine, Jones, Crawford, Welling, & Little, 2010; Gangestad, Haselton, & Buss, 2006; Kenrick & Keefe, 1992; Singh, 1993). Despite this progress in understanding the content of mate preferences, mating research has generated less insight into how humans apply their preferences to select mates (Li & Meltzer, 2015). In par- ticular, it remains unclear how people integrate information on multiple preferences into overall evaluations of their potential mates. Here, I test a hypothesis that humans select mates by integrating mate preferences according to a Euclidean algorithm. Specifically, I compare agent-based models with human samples to test the hypothesis that people who are more desirable according to Euclidean calculations experience greater power of choice on the mating market. Mate preference integration is an essential step in mate choice. When selecting mates, all people face an array of imperfect potentials, each of whom will fulfill some prefer- ences but not others. An intelligent mate may be unkind, a kind mate may be unhealthy, a healthy mate may be unat- tractive, and so on. Evaluating, comparing, and selecting among these imperfect potentials requires a psychology capable of combining information on each potential mate’s assets and blemishes into summary evaluations of their over- all values as mates (Buss & Schmitt, 1993; Jonason, Garcia, Webster, Li, & Fisher, 2015; Jonason, Raulston, & Rotolo, 2012; Li, Bailey, Kenrick, & Linsenmeier, 2002). Human mate choice psychology could use a variety of algorithms to accomplish this integration. A commonly assumed algorithm is a linear combination in which mate value is calculated as the sum of a potential mate’s trait val- ues, weighted by the preferences for each of these values (Buss & Schmitt, 1993; Eastwick, Luchies, Finkel, & Hunt, 2014). Here, preferences act like slopes in a linear regression formula, with a stronger preference for a given trait mani- festing as a stronger effect of that trait on overall mate value. Such linear combinations are powerful and intuitive but have many limitations. Chiefly, they cannot account for estab- lished nonlinear patterns of mate preference and attraction (Lee, Dubbs, Von Hippel, Brooks, & Zietsch, 2014; Li et al., 2002). For instance, men strongly prefer mates who are mod- erately physically attractive over mates who are physically unattractive, but do not discriminate as strongly between moderately and highly physically attractive partners (Li et al., 2002, 2013). Creating these nonlinear effects with a linear combination would require the addition of potentially intractable numbers of parameters. Curvilinear algorithms, 739262PSP XX X 10.1177/0146167217739262Personality and Social Psychology BulletinConroy-Beam research-article 2017 1 University of California, Santa Barbara, USA Corresponding Author: Daniel Conroy-Beam, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9010, USA. Email: conroy-beam@psych.ucsb.edu Euclidean Mate Value and Power of Choice on the Mating Market Daniel Conroy-Beam 1 Abstract Three studies tested the hypothesis that human mate choice psychology uses a Euclidean algorithm to integrate mate preferences into estimates of mate value. In Study 1, a series of agent-based models identify a pattern of results relatively unique to mating markets where individuals high in Euclidean mate value experience greater power of choice: strong preference fulfillment overall and correlations between mate value and (a) preference fulfillment, (b) ideal standards, and (c) partner mate value. Studies 2 and 3 demonstrated that this pattern of results that emerges in human romantic relationships, is specific to mate value as a long-term partner, and is not accounted for by participant biases. These results suggest that human mate choice psychology uses a Euclidean algorithm to integrate mate preferences in mate choice, providing insight into the computational design of human mating psychology and validating this algorithm as a useful tool for future research. Keywords mate choice, mate preferences, assortative mating, computer simulations, evolutionary psychology Received February 14, 2017; revision accepted September 25, 2017