Iñiguez Gerardo, Heydari Sara, Kertész János, Saramäki Jari
Department of Network and Data Science, Central European University, 1100, Vienna, Austria.
Department of Computer Science, Aalto University School of Science, 00076, Aalto, Finland.
Nat Commun. 2023 Aug 26;14(1):5217. doi: 10.1038/s41467-023-40888-5.
Tie strengths in social networks are heterogeneous, with strong and weak ties playing different roles at the network and individual levels. Egocentric networks, networks of relationships around an individual, exhibit few strong ties and more weaker ties, as evidenced by electronic communication records. Mobile phone data has also revealed persistent individual differences within this pattern. However, the generality and driving mechanisms of social tie strength heterogeneity remain unclear. Here, we study tie strengths in egocentric networks across multiple datasets of interactions between millions of people during months to years. We find universality in tie strength distributions and their individual-level variation across communication modes, even in channels not reflecting offline social relationships. Via a simple model of egocentric network evolution, we show that the observed universality arises from the competition between cumulative advantage and random choice, two tie reinforcement mechanisms whose balance determines the diversity of tie strengths. Our results provide insight into the driving mechanisms of tie strength heterogeneity in social networks and have implications for the understanding of social network structure and individual behavior.
社会网络中的关系强度是异质的，强关系和弱关系在网络和个体层面发挥着不同的作用。以个体为中心的网络，即围绕个体的关系网络，显示出较少的强关系和较多的弱关系，电子通信记录证明了这一点。手机数据也揭示了这种模式下持续存在的个体差异。然而，社会关系强度异质性的普遍性和驱动机制仍不明确。在这里，我们研究了数百万人在数月至数年期间的多个互动数据集的以个体为中心的网络中的关系强度。我们发现关系强度分布及其在不同通信模式下的个体层面变化具有普遍性，即使在不反映线下社会关系的渠道中也是如此。通过一个简单的以个体为中心的网络演化模型，我们表明观察到的普遍性源于累积优势和随机选择这两种关系强化机制之间的竞争，这两种机制的平衡决定了关系强度的多样性。我们的结果为社会网络中关系强度异质性的驱动机制提供了见解，并对理解社会网络结构和个体行为具有启示意义。
