Science, Innovation, Technology, and Entrepreneurship Department, University of Exeter Business School, Exeter EX4 4PU, United Kingdom;
Sloan School of Management, Massachusetts Institute of Technology, Cambridge, MA 02142.
Proc Natl Acad Sci U S A. 2021 Feb 16;118(7). doi: 10.1073/pnas.2022761118.
Americans are much more likely to be socially connected to copartisans, both in daily life and on social media. However, this observation does not necessarily mean that shared partisanship per se drives social tie formation, because partisanship is confounded with many other factors. Here, we test the causal effect of shared partisanship on the formation of social ties in a field experiment on Twitter. We created bot accounts that self-identified as people who favored the Democratic or Republican party and that varied in the strength of that identification. We then randomly assigned 842 Twitter users to be followed by one of our accounts. Users were roughly three times more likely to reciprocally follow-back bots whose partisanship matched their own, and this was true regardless of the bot's strength of identification. Interestingly, there was no partisan asymmetry in this preferential follow-back behavior: Democrats and Republicans alike were much more likely to reciprocate follows from copartisans. These results demonstrate a strong causal effect of shared partisanship on the formation of social ties in an ecologically valid field setting and have important implications for political psychology, social media, and the politically polarized state of the American public.
美国人在日常生活和社交媒体上与同党派人士的社交联系更为紧密。然而，这种观察结果并不一定意味着党派认同本身就推动了社交关系的形成，因为党派认同与许多其他因素混淆在一起。在这里，我们在 Twitter 上进行了一项现场实验，测试了党派认同对社交关系形成的因果影响。我们创建了自称支持民主党或共和党的自动账户，并根据其认同的强烈程度进行了区分。然后，我们随机分配了 842 名 Twitter 用户，让他们关注我们的一个账户。用户更有可能反过来关注与自己党派认同相符的机器人账户，这种情况在很大程度上与机器人的认同强度无关。有趣的是，这种优先关注的行为没有党派偏见：民主党人和共和党人都更有可能回应同党派人士的关注。这些结果证明了在生态有效的实地环境中，党派认同对社交关系的形成有很强的因果影响，这对政治心理学、社交媒体以及美国公众政治两极化的现状都具有重要意义。
