Across a variety of economic decision-making situations, we were able to show a more generous attitude towards attractive people; this bias has been shown to be stronger for women, especially when men are the favoring subjects

Voit, M., Weiß, M. & Hewig, J. The benefits of beauty – Individual differences in the pro-attractiveness bias in social decision making. Curr Psychol (2021). Oct 28 2001. https://doi.org/10.1007/s12144-021-02366-3

Abstract: While there already is a huge body of research examining the advantages and disadvantages of physical attractiveness in social and economic decisions, little research has been made to explore the role of individual differences in social decision-making with regard to beauty. To close this scientific gap, we conducted a multiparadigm online study (N = 210; 52% females) in which participants were asked to make decisions in four different economic games facing differently attractive counterparts. Additionally, the personality trait agreeableness was assessed to test for individual differences in decision-making. In exploratory analyses, we also assessed which facet of agreeableness is the most appropriate to predict individual differences in the various economic games. In the study, we were able to replicate the finding of a beauty premium and a plainness penalty but did not find any support for the idea of a beauty penalty. Furthermore, evidence for an opposite-sex advantage was found, which was greater when men were facing women than the other way around. While agreeableness as an overall trait influenced decision making across various paradigms, interactions of distinct facets of agreeableness with the partners’ attractiveness remain heterogeneous and ambiguous. This underlines the importance of integrating the specificity of certain traits in experimental research and the necessity of combining them with different social situations.

Discussion

We investigated how attractiveness and the sex of a social interaction partner affects decision making in four different social and economic paradigms depending on the participants’ sex. To evaluate different aspects of a social interaction, we have chosen the Dictator Game, Trust Game, Ultimatum Game, and Prisoner's Dilemma. Moreover, we examined how the Big Five personality factor agreeableness interacts with decision-making and which particular facet of agreeableness is predictive in the different paradigms.

As expected, participants perceived the attractiveness of their counterparts in line with the intended attractiveness category. Moreover, men rated the range of opposite-sex counterparts’ attractiveness as broader than the range of same-sex partners’ attractiveness. Men thus rated unattractive females as less attractive than unattractive males, whereas attractive females were rated as more attractive than attractive males. Women made no such sex distinctions in the category of attractive and unattractive partners. Hence, men seem to be more judgmental than women towards the partner’s attractiveness when facing a different-sex partner compared to same-sex partners. This is consistent with previous findings (Levy et al., 2008), where men (contrary to women) rated beautiful women as more attractive than beautiful men, which also correlated with enhanced motivational effort for viewing attractive females.

In line with our first hypothesis, we were able to show that in the TG, DG and PD, there was both a clear beauty premium and a plainness penalty, as attractive individuals received more money and higher cooperation rates, whereas unattractive individuals received less money and lower cooperation rates in comparison with moderately attractive individuals. Even in the UG, both a beauty premium and a plainness penalty could be observed for female proposers, when the receiver was male. These findings strengthen the concept of a beauty premium and a plainness penalty, which were firstly described by Hamermesh and Biddle (1993) and further supported by a large body of evidence (e. g., Ma & Hu, 2015; Solnick & Schweitzer, 1999; Wilson & Eckel, 2006). It may be hypothesized that participants show more beneficial economic decisions towards more attractive individuals of both sexes in order to promote positive social relations with them due to their expected qualities (Andreoni & Petrie, 2008; Boyatzis et al., 1998; Dion et al., 1972; Eagly et al., 1991; Feingold, 1992; Langlois et al., 2000; Shinada & Yamagishi, 2014b; Wilson & Eckel, 2006). Accordingly, participants are supposedly less interested in positive interactions and exhibit a lower monetary investment if the social counterpart is of low attractiveness. However, unfair offers from attractive individuals were not rejected more often than unfair offers from less attractive individuals, thus no evidence for a beauty penalty was found. This contradicts our second hypothesis, which was based on the previous findings of Eckel & Wilson (2004) and Andreoni and Petrie (2008) who found attractive individuals who disappointed the participants expectations to be punished harder in a TG and a public goods dilemma, respectively. One has to take into account, though, that in the UG, attractiveness in general seemed to be far less relevant than the size of offer when it comes to decision making. We found no main effect of attractiveness (and only minor advantages for attractive women compared to moderately attractive ones and moderately attractive women compared to unattractive women, when the participant was male) which could explain the absence of a beauty penalty as well. Having identified attractiveness as an important impact factor on social and economic decisions, further research should focus on means to overcome this beauty gap. Moreover, as the beauty gap appears to be greater for women compared to men, unattractive women face a twofold discrimination. Spending so much (well invested) time and energy on discussions of how to overcome the gender gap, society needs to discuss how to deal with this kind of discrimination in everyday and work life. In a recent study placing participants in a hiring position, Tu et al. (2021) found a means to level the gap in an economic context. By asking unattractive individuals to take a powerful body posture, they were rated as being more nonverbally present and the initially found disadvantage in hireability diminished. However, this is not an overarching resolution and may not pay off in social encounters.

Delving into the influence of personality, we could show participants scoring higher on agreeableness as an overall trait tended to be more altruistic, trusting and cooperative. This is consistent with a variety of previous studies who found agreeableness positively linked to cooperation and generosity (e.g., Kagel & McGee, 2014; Koole et al., 2001; Volk et al., 2011; Zhao & Smillie, 2015). Surprisingly and contrary to our third hypothesis, agreeableness did not lead to an increase in decisions in favor of attractive individuals, but even downsized the payment gap between the most and least attractive partners in the DG. As agreeableness was found to play an important role in the inhibition of affect and emotion control (Ode et al., 2008; Robinson, 2007) and the suppression of hostile thoughts (Meier et al., 2006), more agreeable participants may inhibit the urge to favor or discriminate counterparts exclusively based on their (un)attractiveness. However, high levels of agreeableness did not affect the payment and cooperation gap in three out of the four games, but solely led to higher rates of cooperation and payment for all counterparts, regardless of their attractiveness. The abovementioned explanatory approach is thus not completely satisfactory and further research is required. Interestingly, increasing agreeableness scores in women led to decreasing acceptance rates of high and medium offers in the UG. This was not the case for men, who were more likely to accept high offers when scoring high in agreeableness. Further research is needed to determine whether this interaction follows a systematic mechanism or appeared incidentally in our paradigm.

As hypothesized, women benefited more from their attractiveness than men most of the time, contributing to a large body of evidence (Busetta et al., 2013; French, 2002; Kahn et al., 1971; Maestripieri et al., 2017). However, as women were also perceived as more attractive, the origin of this pro-femaleness bias may rather lay in their attractiveness than in their sex. In addition to the pro-femaleness bias, we found evidence for the predicted opposite-sex bias in ratings. The opposite-sex bias was especially large for male participants who preferred attractive female counterparts over attractive male counterparts. This sex difference has already been described in similar studies (e.g., Bhogal et al., 2016) and has also been explained from an evolutionary perspective. While men prefer female mates that show high reproductive value, and thus attractiveness, women emphasize males that present themselves as cooperative and altruistic (see Buss, 1989, for a more detailed discussion). It thus makes sense that males behave in ways that signal resource acquisition, e.g., altruism, generosity, and cooperation when facing highly attractive females. However, in our economic games an opposite-sex bias that depends on attractiveness was only found in DG and PD as evidenced by the three-way interaction of attractiveness, partner sex and participant sex. In these cases, both men and women showed relatively more beneficial economic decisions towards more attractive opposite-sex counterparts. This may be linked to mechanisms of mating behavior in both gender groups and could have an evolutionary background with attractiveness signaling health and fertility for the opposite sex (Maestripieri et al., 2017).

In a recent review, Kou et al. (2020) discuss the underlying cognitive mechanisms influencing the processing of facial attractiveness. They also argue that evolutionary processes may play an important role in both the opposite-sex bias and the femaleness bias when processing differently attractive faces. However, they could not fully discover whether the “female beauty captures attention” or the “opposite-sex beauty captures attention” hypothesis is more likely.

Interestingly, while unattractive women received more money than unattractive men in the DG and in the TG, they faced disadvantages in the PD, where participants cooperated less often with them than with their male counterparts. The reason for these dissimilarities may lay in the differences in the paradigms. Only in the PD, participants rely on their partner’s willingness to cooperate. As they have no other cue than their counterpart’s physical appearance when deciding whether or not to cooperate, the detrimental biases of unattractive counterparts seems to be stronger when facing women than men. In the other paradigms, participants were more generous towards unattractive women than men.

In our explorative analyses we examined which specific facets are especially predictive for decision making in the different paradigms. Concerning the UG and the PD, the facet trust predicted cooperation and acceptance rates to the highest degree. In the TG, increasing scores on the facet of sympathy led to higher amounts of entrusted money. This is counterintuitive as in both the TG and the subscale of trust are supposed to measure trust as a construct and should thus highly correlate. Respectively, in the PD and the UG, one would intuitively expect cooperation to have a stronger influence on decision making than trust. This begs the question whether the subscales of agreeableness do measure distinguishable facets or if the intercorrelation is too high to actually differ between the constructs. It does also underline the importance to include several paradigms and subscales to explore the mechanisms underlying the interaction of attractiveness, the facets of agreeableness and the decision to behave in cooperative, trusting, and altruistic ways.

Taking all the results presented above into account, we found strong support for both a beauty premium and a plainness penalty whereas a beauty penalty could not be observed. Evidence was also found for a stronger pro attractiveness bias for women compared to men, which is in line with a variety of studies. Interestingly, increasing agreeableness did not lead to stronger benefits for attractive counterparts, but rather reduced the beauty gap. Furthermore, in differing economic games, different facets of agreeableness seemed especially predictive. Including multiple games and multiple facets of agreeableness in our study led to a more differentiated and sounder outcome than we would have found with only one specific paradigm.

As a limitation we want to point out the attractiveness differences concerning our counterparts. Both women and men rated moderately attractive females as more attractive than moderately attractive males. This could bias the effects in favor for women and lead to a diminished generalizability. While the reliabilities of the faces were particularly high in the TG and DG (all values of α ≥ 0.85), and acceptable in the UG (most values of α > 0.7), in the PD, however, most reliabilities fell below the critical value of 0.7, as participants differed more severely in their decisions whether or not to cooperate with the different attractive counterparts. Thus, the results for the PD should be taken with caution due to their limited consistency.

To simplify our paradigm, we only included pictures of white, young to middle-aged faces. Future studies should include other races and ages (in both counterparts and participants) to increase the generalizability, as social proximity was found to influence social decisions (Balliet et al., 2014). Moreover, further research is necessary to examine whether the effects are transferable into face-to-face situations.