A relatively large body of work exists examining sex differences in expressiveness; however, there remains little research of differences in expressiveness associated with aging. Observational studies of facial expressivity across ages are limited in part due to the poor scalability of traditional research methods. We collected over 17,000 videos of natural facial behavior using the Internet and performed a large observational study of smiling responses of people ages 18 to 70 years. Using automated facial coding we quantified the presence of smiles as people watched a set of controlled mundane online content. The likelihood of smiles and the duration of smiles increased with age. We attribute this to greater expression of positive emotion in older people. Women smiled more than men over all and gender differences increased significantly with age. We question whether results may be influenced by the effect of age on the accuracy of the automated smile detection; however, validation on a large set of human coded videos shows that the observed effects were not due to smile detection performance.

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褪色的笑容？从青春期到老年期微笑的大规模观察性研究

有大量工作研究了表现力的性别差异；然而，关于与衰老相关的表现力差异的研究仍然很少。由于传统研究方法的可扩展性差，跨年龄面部表情的观察研究受到限制。我们使用互联网收集了 17,000 多个自然面部行为的视频，并对 18 至 70 岁人群的微笑反应进行了大型观察研究。使用自动面部编码，我们量化了人们观看一组受控的平凡在线内容时微笑的存在。微笑的可能性和微笑的持续时间随着年龄的增长而增加。我们将此归因于老年人更多地表达积极情绪。总体而言，女性的笑容比男性多，性别差异随着年龄的增长而显着增加。我们质疑结果是否会受到年龄对自动微笑检测准确性的影响；然而，对大量人类编码视频的验证表明，观察到的效果不是由于微笑检测性能。