by Tom S. Roth & Iliana Samara
Maybe you still cherish vivid memories of your first date with your partner. Maybe you remember what they looked like, the sound of their voice, or even their scent! During first encounters, we are confronted with multiple sources of information, encompassing a range of modalities. It is well known that this information shapes our opinion about potential partners. However, what remains unknown is which of these sources is most important for partner choice. In an article that recently appeared in Evolution and Human Behavior, we examined this by exploring how attractiveness on different modalities relates to speed-date outcome.
A plethora of studies has investigated the role of visual attractiveness in partner choice. For example, when people go on a date with a visually attractive partner, they are more likely to seek another date with them. However, it has recently been suggested that when studying attractiveness we should look further than visual information, and include scent and sound as well. Even though some studies have investigated the attractiveness of scent and sound, their effect on actual partner choice remains unclear. Therefore, in our study, we combined multimodal attractiveness ratings with a natural paradigm to study partner choice, namely speed-dating. Speed-dates strongly reflect natural partner choice situations, and are therefore great tools to study partner choice in humans.
To study the role of multimodal attractiveness in partner choice, we invited a group of 67 heterosexual participants (34 women and 33 male), between the ages of 18 and 26 years old, to the lab. These participants were divided over 4 groups, that were each tested in a different time slot. Every group had approximately the same number of men and women. The experiment consisted of three stages: a sample collection stage, a sample rating stage, and a speed-dating stage.
In each group, we started by collecting samples. After arriving at the lab, we took a standardized portrait picture of each participant, recorded their voice while they were reading out a standardized Dutch text, and we asked them to bring a t-shirt that they had worn during the night. In this way, we had a sample that could be rated for visual, auditory, and olfactory attractiveness from each participant. In the sample-rating part of the experiment, participants rated the attractiveness of all the samples that we gathered from the opposite-sex participants on a 1 to 7 scale, with 1 meaning very unattractive and 7 meaning very attractive. Thus, the men rated the attractiveness of the picture, voice recording and t-shirt scent of the women in their timeslot, while the women rated the samples of the men in their timeslot. Finally, after completing all the rating tasks, participants took part in the speed-dating part of the experiment. Each participant had a maximum of 10 speed-dates, depending on the number of opposite-sex participants in their timeslot. At the end of each date, participants indicated whether they would like to go on another date with their partner, and how attractive they found their partner. Furthermore, people that both indicated that they wanted to meet their partner again, received each other’s contact information, so that they could meet up again after the experiment.
We investigated how well the ratings of the different modalities predicted the date outcome, in this case, how likely participants were to seek another date with their partner. We found that, as would be expected, visual information was the most important predictor of the willingness to date again for both men and women. Regarding the auditory information, we found that vocal attractiveness seemed to have a small positive influence on willingness to meet again in men, but not women. For olfactory information, we found the opposite pattern. There was no clear effect in men, but in women there was a surprising negative association. In other words, the more pleasant an odor was rated before the speed-dating paradigm, the less likely women were to indicate that they would go on another date with their partner.
This study is the first one that distinguishes between visual, auditory and olfactory attractiveness, and compares their importance in partner choice. In line with previous studies, we found that facial attractiveness was the strongest predictor for willingness to go on another date. This finding is not surprising, given that humans are visually well-equipped, and strongly inclined to pay more attention to visual information than other modalities.
When it comes to sound, auditory attractiveness seemed to be somewhat important for men, but not women. Nonetheless, this could be due to naturally occurring voice fluctuations during the date, for example people might tend to modulate their pitch when speaking to someone that they consider attractive. Importantly, this finding could be due to the noise in the room, as all group dates were hosted at the same time. This might have led to the voice of the partner being perceived as different compared to the recording.
Regarding the olfactory attractiveness, we found no discernible pattern for men, and a small but surprising negative association for women. This finding could be due to people wearing perfumed hygienic products before putting on the t-shirt (e.g., deodorant). Even though participants were instructed not to use such products before and while wearing the t-shirt, they might have wanted to mask their natural body odor. Therefore, it could be that the smell samples represent diplomatic odor (i.e., combination of natural body odor and hygienic products), thereby obscuring the effect of scent attractiveness on partner choice.
Visual attraction seems to be most important during first dates, while voice and scent seem to have little to no effect.
An interesting theoretical explanation for the fact that auditory and olfactory attractiveness seem to have little to no effect on mate choice compared to visual attractiveness could be that visual, auditory, and olfactory information become important in different stages of the relationship. In other words, upon meeting a new partner, visual information could act as a filter, ensuring that a sufficiently attractive partner is selected. Following this stage, auditory information and olfactory gradually might become more decisive for partner selection and maintenance. Future research can investigate whether this is indeed the case.
In sum, visual attraction seems to be most important during first dates, while voice and scent seem to have little to no effect. Thus, while attractiveness might indeed be multimodal, when it comes to first encounters it seems that the eyes have it.