People's perceptions about the frequency of attributes in their social networks sometimes show false consensus, or overestimation of the frequency of own attributes, and sometimes false uniqueness, or underestimation of the frequency. Here we show that both perception biases can emerge solely from the structural properties of social networks. Using a generative network model, we show analytically that perception biases depend on the level of homophily and its asymmetric nature, as well as on the size of minority group. Model predictions correspond to empirical data from a cross-cultural survey study and to numerical calculations on six real-world networks. We also show in what circumstances individuals can reduce their biases by relying on perceptions of their neighbors. This study advances our understanding of the impact of network structure on perception biases and offers a quantitative approach for addressing related issues in society. arXiv:1710.08601v4 [physics.soc-ph] 22 Jul 2019
Empirical networksThe first network, Brazilian network, captures sexual contact between sex workers and sex buyers 46 . The network consists of 16, 730 nodes and 39, 044 edges. There are 10, 106 sex workers and 6, 624 sex buyers (minority-group size f a = 0.4). In this network, no edges among members of the same group exist resulting in the Newman's assortativity (q = −1), and consequently, the network is purely heterophilic (h = 0).The second network is an online Swedish dating network from PussOKram.com (POK) 47 . This network contains 29, 341 nodes with strong heterophily (h = 0.17, q = −0.65). Given the high bipartivity of the network, we are able to infer the group of nodes using the max-cut greedy algorithm. The results are in good agreement with the bipartivity reported 48 . Since the group definition is arbitrary, we label the nodes based on their relative group size as minority gender and majority gender. Here, the fraction of the minority in the network is 0.44.The third network is a Facebook network of a university in the United States (USF51) 49 . The network is composed of 6,253 nodes and includes information about individuals' gender. In this network male students are in the minority, occupying 42% of the network, and the network exhibits a small heterophily 49 (q = −0.06, h = 0.48).The fourth network is extracted from the collaborative programming environment GitHub. The network is a snapshot of the community (extracted August 4, 2015) that includes information about the first name and family name of the programmers. We used the first name and family name to infer the gender of the programmers 50 . After we removed ambiguous names, the network consisted of 120, 338 men and 7, 330 women. Here, women belong to the minority group and represent only about 6% of the population. The network displays a moderately symmetric gender homophily of 0.53 (q = 0.07).The fifth network depicts scientific collaborations in computer science and is extracted from Digital Bibliography & Library Project's website (DBLP) 51 . We used a new...