The world’s languages are unfathomably diverse. At the same time, this complexity is not random: Across human languages—whether written, spoken, or signed—there are observable statistical regularities known as ‘language laws.’ These laws describe how communication tends toward efficiency, for example by shortening words while retaining their meaning, such as the reduction of “photograph” to “photo.” However, whether similar patterns of efficiency apply to non-linguistic forms of communication, such as facial expressions or gestures, remains unclear. Additionally, it is still unknown at what stage in human development this communicative efficiency begins, as there has been limited research on preverbal children.
Researching preverbal children’s communication and great ape gestures represent just the right tool. Gesture has played a prominent role in studies of early childhood language acquisition, with an emphasis on gestures as the beginning of intentional communication and the study of great ape gestures is essential for our understanding of language evolution, as it is the best-known intentional system of animal communication. However, framing great ape gestural communication in the light of efficiency is a recent effort, with few studies testing chimpanzee gestures for language-like efficiency patterns.
Recent research has begun to explore this by testing two well-known linguistic laws—Zipf’s law of brevity and Menzerath’s law—within chimpanzee gestural communication. These laws regulate the frequency and duration of communicative units, both when used singly and when combined into longer strings (gestural sequences or sentences). Although these studies have provided compelling evidence that chimpanzee gestures follow similar patterns to human languages, their focus on a single chimpanzee community limits broader conclusions about the evolution of human language.
Language is social and to understand its evolution one must look at how communication is used between individuals, with my PhD showing a first indication that social cohesiveness seems to go hand in hand with communicative efficiency. Strikingly, the community that showed similar social dynamics to early human groups (small and highly cohesive) showed efficiency patterns close to human languages.
By analysing child gestural data from different communities around the globe and combining them with ape data to understand the evolutionary origins of efficiency, I will expand and refine my PhD work and make contributions to our understanding of where human language originated. By applying both consolidated and newly developed computational linguistic methodologies developed during my PhD to non-human and human gestural communication, I will try to find the right recipe for the emergence of efficient human communication.
Research Area: RA3: Language, Culture, and Education
Publications:
Mielke, A., Badihi, G., Graham, K. E., Grund, C., Hashimoto, C., Piel, A. K., Safryghin, A., Slocombe, K. E., Stewart, F., Wilke, C., Zuberbühler, K., & Hobaiter, C. (2024). Many morphs: Parsing gesture signals from the noise. Behavior Research Methods.
Grund, C., Badihi, G., Graham, K. E., Safryghin, A., & Hobaiter, C. (2023). GesturalOrigins: A bottom-up framework for establishing systematic gesture data across ape species. Behavior Research Methods.
Badihi, G., Graham, K. E., Fallon, B., Safryghin, A., Soldati, A., Zuberbühler, K., & Hobaiter, C. (2023). Dialects in leaf-clipping and other leaf-modifying gestures between neighbouring communities of East African chimpanzees. Scientific Reports, 13(1).
Safryghin, A., Cross, C., Fallon, B., Heesen, R., Ferrer-i-Cancho, R., & Hobaiter, C. (2022). Variable expression of linguistic laws in ape gesture: A case study from chimpanzee sexual solicitation. Royal Society Open Science, 9(11).
Graham, K. E., Badihi, G., Safryghin, A., Grund, C., & Hobaiter, C. (2022). A socio-ecological perspective on the gestural communication of Great Ape species, individuals, and social units. Ethology Ecology & Evolution, 34(3), 235–259.
Safryghin, A., Hebesberger, D. V., & Wascher, C. A. (2019). Testing for behavioral and physiological responses of domestic horses (Equus caballus) across different contexts – consistency over time and effects of context. Frontiers in Psychology, 10.
Social Media Links:
www.linkedin.com/in/alexandra-safryghin