McGrath Nicky, Phillips Clive J C, Burman Oliver H P, Dwyer Cathy M, Henning Joerg
School of Veterinary Sciences, University of Queensland, Gatton, Queensland 4343, Australia.
Institute of Veterinary Medicine and Animal Science, Estonia University of Life Sciences, Tartu, Estonia.
R Soc Open Sci. 2024 Jan 3;11(1):231284. doi: 10.1098/rsos.231284. eCollection 2024 Jan.
Humans can decode emotional information from vocalizations of animals. However, little is known if these interpretations relate to the ability of humans to identify if calls were made in a rewarded or non-rewarded context. We tested whether humans could identify calls made by chickens () in these contexts, and whether demographic factors or experience with chickens affected their correct identification context and the ratings of perceived positive and negative emotions (valence) and excitement (arousal) of chickens. Participants ( = 194) listened to eight calls when chickens were anticipating a reward, and eight calls in non-rewarded contexts, and indicated whether the vocalizing chicken was experiencing pleasure/displeasure, and high/low excitement, using visual analogue scales. Sixty-nine per cent of participants correctly assigned reward and non-reward calls to their respective categories. Participants performed better at categorizing reward-related calls, with 71% of reward calls classified correctly, compared with 67% of non-reward calls. Older people were less accurate in context identification. Older people's ratings of the excitement or arousal levels of reward-related calls were higher than younger people's ratings, while older people rated non-reward calls as representing higher positive emotions or pleasure (higher valence) compared to ratings made by younger people. Our study strengthens evidence that humans perceive emotions across different taxa, and that specific acoustic cues may embody a homologous signalling system among vertebrates. Importantly, humans could identify reward-related calls, and this ability could enhance the management of farmed chickens to improve their welfare.
人类能够从动物的叫声中解码情感信息。然而,对于这些解读是否与人类识别叫声是在有奖励还是无奖励情境下发出的能力相关,我们却知之甚少。我们测试了人类是否能够识别鸡在这些情境下发出的叫声,以及人口统计学因素或与鸡的接触经历是否会影响他们对情境的正确识别,以及对鸡所感知到的积极和消极情绪(效价)及兴奋程度(唤醒度)的评分。参与者(n = 194)聆听了鸡在期待奖励时发出的八次叫声,以及无奖励情境下的八次叫声,并使用视觉模拟量表指出发声的鸡是在体验愉悦/不悦,以及兴奋程度是高/低。69%的参与者将奖励叫声和无奖励叫声正确地归类到各自的类别中。参与者在对与奖励相关的叫声进行分类时表现更好,71%的奖励叫声被正确分类,而无奖励叫声的正确分类率为67%。老年人在情境识别方面不太准确。老年人对与奖励相关叫声的兴奋或唤醒水平的评分高于年轻人,而与年轻人的评分相比,老年人将无奖励叫声评为代表更高的积极情绪或愉悦(更高的效价)。我们的研究进一步证明,人类能够感知不同分类群中的情感,并且特定的声学线索可能体现了脊椎动物之间同源的信号系统。重要的是,人类能够识别与奖励相关的叫声,这种能力可以加强对养殖鸡的管理以改善它们的福利。