Workshops

The evolution of human conspicuous ocular morphology and its role in the evolution of language

Slawomir Wacewicz, Juan Olvido Perea-García, Dariusz Danel, Przemyslaw Zywiczynski, Antonio Benítez-Burraco, Theresa Matzinger

Human eyes are exceptional – they are unusually horizontally elongated and have homogeneously pale sclerae, which makes them highly conspicuous and important signaling devices. Therefore, research on the appearance of human eyes makes a rare connection between human morphological and behavioral uniqueness. Also, it addresses key topics of hominin evolution, such as cooperation, self-domestication and nonverbal signaling, all of which are closely linked to the evolution of language: First, the conspicuousness of the human eye may have enabled ocular signals that scaffolded prelinguistic communication such as ostensive cues (i.e. eye contact for initiating communication) and indexes (pointing with your eyes). Secondly, enhanced gaze-following may have played a key role in the evolution of in-group cooperation (cf. the “cooperative eye” hypothesis), which is an essential condition for all forms of linguistic communication. Thirdly, changes of pigmentation are typical by-products of domestication, which leads to reduced aggression, increased social tolerance and prosociality, suggesting that a depigmented sclera might have been associated with the type of sociality necessary for the development of language.

In this workshop, we discuss state-of-the-art knowledge on the external appearance of human eyes as compared to those of non-human primates. We will discuss how these different ocular morphologies may be connected to different forms of communication. We will focus on current methods, from sampling strategies to meaningful measurements of ocular morphology. We will also explore the proximate mechanisms whereby selection against aggression may have contributed to the emergence of human communication, including the evolution of morphology and behavior. Our workshop will provide a more nuanced and holistic understanding of the many factors that contributed to the highly specialized communicative abilities of humans.

Confirmed speakers: Judith Burkart, Kai Caspar, Fumihiro Kano