  Moral psychology is a domain that deals with moral identity, appraisals and
emotions. Previous work has primarily focused on moral development and the
associated role of culture. Knowing that language is an inherent element of a
culture, we used the social media platform Twitter to compare moral behaviors
of Japanese tweets with English tweets. The five basic moral foundations, i.e.,
Care, Fairness, Ingroup, Authority and Purity, along with the associated
emotional valence were compared between English and Japanese tweets. The tweets
from Japanese users depicted relatively higher Fairness, Ingroup, and Purity,
whereas English tweets expressed more positive emotions for all moral
dimensions. Considering moral similarities in connecting users on social media,
we quantified homophily concerning different moral dimensions using our
proposed method. The moral dimensions Care, Authority and Purity for English
and Ingroup, Authority and Purity for Japanese depicted homophily on Twitter.
Overall, our study uncovers the underlying cultural differences with respect to
moral behavior in English- and Japanese-speaking users.
