Centre for Language Evolution Studies

Kontakt Faculty of Humanities
Collegium Maius, Room 26,
ul. Fosa Staromiejska 3, 87-100 Toruń

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

workshop at the Joint Conference of Language Evolution, Kanazawa (Japan), 13:30 – 15:30 Conference room 5/6

and online, 5 Sep 2022

images of eyes of various animal species, indicating sclera pigmentation


Workshop abstract

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.



13:30 – 13:55 JST (6:30 – 6:55 CEST): Sławomir Wacewicz, Juan Olvido Perea-García, Dariusz Danel, Przemysław Żywiczyński, Antonio Benítez-Burraco, Theresa Matzinger (organizers): Introduction –  state of current research & open questions Abstract VIDEO OF THE TALK

13:55 – 14:20 JST (6:55 – 7:20 CEST): Judith Burkhart: What’s in a gaze? Cooperative breeding and the evolution of cooperative signaling Abstract  

14:20 – 14:45 JST (7:20 – 7:45 CEST): Kai CasparSelf-domestication and scleral depigmentation: lessons from primates and other mammals Abstract

14:45 – 15:10 JST (7:45 – 8:10 CEST): Fumihiro Kano: What is unique about the human eye and how communicative is it? Comparative perspective on the evolution of human white sclera Abstract

15:10 – 15:30 JST (8:10 – 8:30 CEST): Panel discussion


The „Evolution of human conspicuous ocular morphology and its role in the evolution of language” seminar inaugurates the Annual Ocular Morphology Seminar series.


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