  Moral foundations theory explains variations in moral behavior using innate
moral foundations: Care, Fairness, Ingroup, Authority, and Purity, along with
experimental supports. However, little is known about the roles of and
relationships between those foundations in everyday moral situations. To
address these, we quantify moral foundations from a large amount of online
conversations (tweets) about moral topics on the social media site Twitter. We
measure moral loadings using latent semantic analysis of tweets related to
topics on abortion, homosexuality, immigration, religion, and immorality in
general, showing how the five moral foundations function in spontaneous
conversations about moral violating situations. The results indicate that
although the five foundations are mutually related, Purity is the most
distinctive foundation and Care is the most dominant foundation in everyday
conversations on immorality. Our study shows a new possibility of natural
language processing and social big data for moral psychology.
