Although affective expressions of individuals have been extensively studied using social media, research has primarily focused on the Western context. There are substantial differences among cultures that contribute to their affective expressions. This paper examines the differences between Twitter (X) in the United States and Sina Weibo posts in China on two primary dimensions of affect - valence and arousal. We study the difference in the functional relationship between arousal and valence (so-called V-shaped) among individuals in the US and China and explore the associated content differences. Furthermore, we correlate word usage and topics in both platforms to interpret their differences. We observe that for Twitter users, the variation in emotional intensity is less distinct between negative and positive emotions compared to Weibo users, and there is a sharper escalation in arousal corresponding with heightened emotions. From language features, we discover that affective expressions are associated with personal life and feelings on Twitter, while on Weibo such discussions are about socio-political topics in the society. These results suggest a West-East difference in the V-shaped relationship between valence and arousal of affective expressions on social media influenced by content differences. Our findings have implications for applications and theories related to cultural differences in affective expressions.

翻译：尽管个体情感表达已通过社交媒体得到广泛研究，但相关研究主要集中于西方语境。不同文化间存在显著差异，这些差异影响着各自的情感表达方式。本文考察了美国Twitter（X）与中国新浪微博用户的情感表达在效价与 arousal 两个核心维度上的差异。我们比较了中美两国个体在 arousal 与效价之间功能关系（即所谓V形关系）的差异，并探讨了相关的主题内容差异。此外，我们通过关联两个平台的词汇使用与话题内容来解读其差异。研究发现：Twitter用户的情感强度在负面与正面情绪间的变化不如微博用户明显，且其 arousal 水平随情绪强度升高而陡增更为显著。从语言特征来看，Twitter上的情感表达多与个人生活及感受相关，而微博上则多涉及社会政治议题。这些结果表明，社交媒体中情感表达效价与 arousal 间的V形关系存在东西方差异，且受内容差异影响。本研究对跨文化情感表达的应用与理论具有启示意义。