What determines the much-discussed “first impression” when we meet new people in private or professional contexts? And what influence can our characteristics and needs have on the perception of another person during this encounter? In the following book chapter, we will explore these questions and first introduce the dimensions by which the perception of unfamiliar people can be characterized. We then draw parallels to the relevant dimensions in the perception of potential partners and discuss the importance of the domains depending on the characteristics of the observing person. We will argue that certain people (targets) are perceived differently by certain observers (perceivers) (target x perceiver interaction). Here, we focus on gender as a relevant perceiver variable. Furthermore, we will demonstrate that the differing importance in the evaluation of partner characteristics is not only reflected in self-reporting. There are already initial findings that suggest target, perceiver, and target × perceiver interaction effects in the automatic processing of partner characteristics at a basic cognitive level. Finally, we summarize which questions empirical research has already answered and which are still open. From our perspective, a systematic and comprehensive understanding of automatic processing in person perception opens up an interesting field of research for evolutionary social sciences, to derive and test theory-driven hypotheses about the influence of “culture” at various stages of processing, starting from very basic automatic processes at the level of perception and attention, to very controlled and distorted responses in self-reporting.