Abstract：
BACKGROUND: The Fijian \'Bula Smile\' is often described as the world\'s friendliest; however, its description remains anecdotal.
OBJECTIVE: This study aimed to describe and compare the dynamics of Fijians\' smiles with those of New Zealand Europeans.
METHODS: An observational study was conducted on two ethnic groups, Fijians (FJ; N = 23) and New Zealand Europeans (NZ; N = 23), age- and gender-matched. All participants were asked to watch amusing videos, and their reactions were video recorded. The videos were analysed by software to assess the frequency, duration, intensity and genuineness of smiling episodes. Based on the Facial Action Coding System, Action Unit 6 (AU6-cheek raiser), Action Unit 12 (AU12-lip corner puller) and Action Unit 25 (AU25-lips apart) were assessed. Data were analysed by generalised linear models after adjusting for personality traits.
RESULTS: Fijians smiled longer than New Zealand Europeans (+19.9%; p = .027). Mean intensity of AU6 (+1.0; 95%CIs = 0.6-1.5; p < .001), AU12 (+0.5; 95%CIs = 0.1-0.9; p = .008) and AU25 (+22.3%; 95%CIs = 7.3%-37.3%; p = .005) were significantly higher in FJ group than the NZ group.
CONCLUSIONS: Smiling features of Fijians and New Zealanders showed objective differences, the most distinctive being a higher activation of the Duchenne\'s marker (AU6) in the Fijian group, which is regarded as a sign of smile genuineness.
OBJECTIVE: This study aimed to describe and compare the dynamics of Fijians\' smiles with those of New Zealand Europeans.
METHODS: An observational study was conducted on two ethnic groups, Fijians (FJ; N = 23) and New Zealand Europeans (NZ; N = 23), age- and gender-matched. All participants were asked to watch amusing videos, and their reactions were video recorded. The videos were analysed by software to assess the frequency, duration, intensity and genuineness of smiling episodes. Based on the Facial Action Coding System, Action Unit 6 (AU6-cheek raiser), Action Unit 12 (AU12-lip corner puller) and Action Unit 25 (AU25-lips apart) were assessed. Data were analysed by generalised linear models after adjusting for personality traits.
RESULTS: Fijians smiled longer than New Zealand Europeans (+19.9%; p = .027). Mean intensity of AU6 (+1.0; 95%CIs = 0.6-1.5; p < .001), AU12 (+0.5; 95%CIs = 0.1-0.9; p = .008) and AU25 (+22.3%; 95%CIs = 7.3%-37.3%; p = .005) were significantly higher in FJ group than the NZ group.
CONCLUSIONS: Smiling features of Fijians and New Zealanders showed objective differences, the most distinctive being a higher activation of the Duchenne\'s marker (AU6) in the Fijian group, which is regarded as a sign of smile genuineness.
摘要：
背景：斐济人“布拉微笑”通常被描述为世界上最友好的人；但是，它的描述仍然是轶事。
目的：本研究旨在描述和比较斐济人与新西兰欧洲人的微笑动态。
方法：对两个种族进行了观察性研究，斐济人（FJ;N=23）和新西兰欧洲人（NZ;N=23），年龄和性别匹配。所有参与者都被要求观看有趣的视频，他们的反应被录像记录下来。通过软件分析视频以评估频率，持续时间,微笑事件的强度和真实性。基于面部动作编码系统，行动单元6(AU6-cheekraiser)，评估行动单元12（AU12-唇角拉拔器）和行动单元25（AU25-嘴唇分开）。调整人格特质后，通过广义线性模型对数据进行分析。
结果：斐济人比新西兰欧洲人笑得更长（+19.9%；p=0.027）。AU6的平均强度（+1.0；95CIs=0.6-1.5；p<.001），FJ组AU12(+0.5;95CIs=0.1-0.9;p=.008)和AU25(+22.3%;95CIs=7.3%-37.3%;p=.005)显著高于NZ组。
结论：斐济人和新西兰人的微笑特征显示出客观差异，最独特的是斐济群体中Duchenne标记（AU6）的更高激活，这被认为是微笑真诚的标志。
目的：本研究旨在描述和比较斐济人与新西兰欧洲人的微笑动态。
方法：对两个种族进行了观察性研究，斐济人（FJ;N=23）和新西兰欧洲人（NZ;N=23），年龄和性别匹配。所有参与者都被要求观看有趣的视频，他们的反应被录像记录下来。通过软件分析视频以评估频率，持续时间,微笑事件的强度和真实性。基于面部动作编码系统，行动单元6(AU6-cheekraiser)，评估行动单元12（AU12-唇角拉拔器）和行动单元25（AU25-嘴唇分开）。调整人格特质后，通过广义线性模型对数据进行分析。
结果：斐济人比新西兰欧洲人笑得更长（+19.9%；p=0.027）。AU6的平均强度（+1.0；95CIs=0.6-1.5；p<.001），FJ组AU12(+0.5;95CIs=0.1-0.9;p=.008)和AU25(+22.3%;95CIs=7.3%-37.3%;p=.005)显著高于NZ组。
结论：斐济人和新西兰人的微笑特征显示出客观差异，最独特的是斐济群体中Duchenne标记（AU6）的更高激活，这被认为是微笑真诚的标志。
