Page 88 - Emotions through the eyes of our closest living relatives- Exploring attentional and behavioral mechanisms

Chapter 4
Abstract
Perceiving emotions in others is at the foundation of higher-order social cognition. Currently, we do not fully understand how evolution shaped the cognitive processes underlying emotion perception. Bonobos (Pan paniscus) are our closest relatives, and have more developed brain structures involved in emotion processing and exhibit stronger emotion regulation abilities compared to other apes. This makes bonobos an important animal model for understanding the evolutionary development of emotion perception. Here, we investigated how bonobos and humans attend to emotionally- laden scenes in a preferential looking task using eye-tracking. With Bayesian mixed modeling, we established that in both species attention is spontaneously sustained to emotional scenes of conspecifics rather than heterospecifics. Moreover, scenes displaying distress held attention longest compared to neutral scenes, consistent with studies finding an initial attentional bias towards potentially threatening signals. Additionally, bonobos and humans attended longer to sexual scenes compared to neutral scenes, in line with sex being highly rewarding in both species. Humans also attended longer to scenes involving grooming and embracing, as well as play. These findings suggest that emotional signals are relevant to bonobos and that eye-tracking can provide a unique window into apes’ affective capacities.
Based on:
Van Berlo, E., Kim, Y., & Kret, M. E. (2021). Attentional selectivity for emotions: humans and bonobos compared. Manuscript submitted for publication.
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