Page 23 - Demo

General introduction211inspect multiple conspecifics of the opposite sex. Based on different criteria, such as proximity, affiliative behavior, courtship behavior, and agonistic behavior, the preference of the chooser can be assessed. In most studies, half of the choosers are then paired with their preferred mate, while the other half is paired with a non-preferred mate. A qualitative review across taxa that examined results from such setups showed that quantitative and qualitative measures of reproductive output were almost exclusively higher for animals that were allowed to choose their partner (Martin-Wintle et al., 2019). This suggests that selecting individuals based on attractive traits might indeed facilitate successful reproduction.Concluding, studies on non-human animals provide evidence for the assumption that attractive traits might inform conspecifics about mate quality, and that selecting for attractive traits might increase reproductive success. This raises the question of whether these assumptions also hold for humans. Human mate choiceWhen considering evidence for both assumptions in human populations, a more complex pattern emerges. With regard to the first assumption, a clear link between visual attractiveness and markers of health has not been established yet: while some studies claim a positive association (Hönekopp et al., 2004; Mengelkoch et al., 2022; Nedelec & Beaver, 2014), other studies found null results (Cai et al., 2019; Jones et al., 2021; Pátková et al., 2022). When looking at specific traits that are considered attractive, a similar pattern emerges. A clear example of this is facial symmetry: humans rate symmetrical faces as more attractive (Rhodes, 2006) and healthy looking (Rhodes et al., 2007). It has also been suggested that symmetry might be a reliable indicator of health (Valen, 1962). However, studies have mostly failed to identify such a relationship (Hönekopp et al., 2004; Pound et al., 2014; Rhodes et al., 2001). It is important to note that these null results only show that the association between health and attractiveness is unclear in our current environment. A potential explanation for these equivocal findings is that health and attractiveness were related in our evolutionary past, but that this association has been obfuscated by recent innovations, such as modern medicine and beauty products (Thornhill & Gangestad, 1999). Altogether, there is no unequivocal evidence for a link between attractiveness and health in current human populations.Tom Roth.indd 21 08-01-2024 10:41