Sarabian data visualcond1 ESM from Avoidance of biological contaminants through sight, smell and touch in chimpanzees.

Avoiding biological contaminants is a well-known manifestation of the adaptive system of disgust. In theory, animals evolved with such a system to prevent pathogen and parasite infection. Bodily products are human-universal disgust elicitors, but whether they also elicit avoidance behaviour in non-human primates has yet to be tested. Here, we report experimental evidence that potential exposure to biological contaminants (faeces, blood, semen), as perceived via multiple sensory modalities (visual, olfactory, tactile), might influence feeding decisions in chimpanzees (<i>Pan troglodytes troglodytes</i>)—our closest phylogenetic relatives. Although somewhat mixed, our results do show increased latencies to feed, tendencies to maintain greater distances from contaminants and/or outright refusals to consume food in test versus control conditions. Overall, these findings are consistent with the parasite avoidance theory of disgust, although the presence of biological contaminants did not preclude feeding entirely. The avoidance behaviours observed hint at the origins of disgust in humans, and further comparative research is now needed.

规避生物污染物，是厌恶情绪适应系统的经典表现形式。从理论上讲，动物演化出这类系统，目的是抵御病原体与寄生虫的感染。体液是全人类共通的厌恶触发源，但这类物质是否也能引发非人灵长类的规避行为，仍有待实验验证。本研究通过实验证实：当黑猩猩（Pan troglodytes troglodytes——我们在系统发育上亲缘关系最近的亲属）通过视觉、嗅觉、触觉等多种感官模态感知到潜在的生物污染物（粪便、血液、精液）时，其进食决策可能会受到影响。尽管实验结果存在一定异质性，但相较于对照组，实验组确实表现出进食潜伏期延长、与污染物保持更远距离的倾向，以及直接拒绝食用食物的情况。总体而言，本研究结果与厌恶情绪的寄生虫规避理论相符，尽管生物污染物的存在并未完全阻止黑猩猩的进食行为。本次观测到的规避行为，为人类厌恶情绪的起源提供了初步线索，未来仍需开展更多比较研究。