Computational folkloristics, which is rooted in the movement to make folklore studies more scientific, has transformed the way researchers in humanities detect patterns of cultural transmission in large folklore collections. This interdisciplinary study contributes to the literature through its application of Bayesian statistics in analyzing Vietnamese folklore. By breaking down 307 stories in popular Vietnamese folktales and major story collections and categorizing their core messages under the values or anti-values of Confucianism, Buddhism, and Taoism, the study shows how the Bayesian method helps discover an underlying behavioural phenomenon called "cultural additivity." The term, which is inspired by the principle of additivity in probability, adds to the voluminous works on syncretism, creolization and hybridity in its technical dimension. Here, to evaluate how the values and norms of the aforementioned three religions ("tam giáo" 三教) co-exist, interact, and influence Vietnamese society, the study proposes three models of additivity for religious faiths: (a) no additivity, (b) simple additivity, and (c) complex additivity. The empirical results confirm the existence of "cultural additivity" : not only is there an isolation of Buddhism in the folktales, there is also a higher possibility of interaction or addition of Confucian and Taoist values even when these two religions hold different value systems (β {VT.VC} = 0.86). The arbitrary blend of the three religions is an example of the observed phenomenon of Vietnamese people selecting and adding ideas, beliefs, or artefacts-which may sometimes appear contradictory to principles of their existing beliefs-to their culture. The behavioural pattern is omnipresent in the sense that it can also be seen in Vietnamese arts, architecture, or adoption of new ideas and religions, among others. The "cultural additivity" concept, backed by robust statistical analysis, is an attempt to fill in the cultural core pointed out by syncretism and account for the rising complexity of modern societies.

No abstract

The study of cultural evolution has taken on an increasingly interdisciplinary and diverse approach in explicating phenomena of cultural transmission and adoptions. Inspired by this computational movement, this study uses Bayesian networks analysis, combining both the frequentist and the Hamiltonian Markov chain Monte Carlo (MCMC) approach, to investigate the highly representative elements in the cultural evolution of a Vietnamese city's architecture in the early 20th century. With a focus on the façade design of 68 old houses in Hanoi's Old Quarter (based on 78 data lines extracted from 248 photos), the study argues that it is plausible to look at the aesthetics, architecture and designs of the house façade to find traces of cultural evolution in Vietnam, which went through more than six decades of French colonization and centuries of sociocultural influence from China. The in-depth technical analysis, though refuting the presumed model on the probabilistic dependency among the variables, yields several results, the most notable of which is the strong influence of Buddhism over the decorations of the house façade. Particularly, in the top 5 networks with the best Bayesian Information criterion (BIC) scores and p<0.05, the variable for decorations (DC) always has a direct probabilistic dependency on the variable B for Buddhism. The paper then checks the robustness of these models using Hamiltonian MCMC method and find the posterior distributions of the models' coefficients all satisfy the technical requirement. Finally, this study suggests integrating Bayesian statistics in social sciences in general and for study of cultural evolution and architectural transformation in particular.

Every year, the Vietnamese people reportedly burned about 50,000 tons of joss papers, which took the form of not only bank notes, but iPhones, cars, clothes, even housekeepers, in hope of pleasing the dead. The practice was mistakenly attributed to traditional Buddhist teachings but originated in fact from China, which most Vietnamese were not aware of. In other aspects of life, there were many similar examples of Vietnamese so ready and comfortable with adding new norms, values, and beliefs, even contradictory ones, to their culture. This phenomenon, dubbed "cultural additivity", prompted us to study the coexistence , interaction, and influences among core values and norms of the Three Teachings-Confucianism, Buddhism, and Taoism-as shown through Vietnamese folktales. By applying Bayesian logistic regression, we evaluated the possibility of whether the key message of a story was dominated by a religion (dependent variables), as affected by the appearance of values and anti-values pertaining to the Three Teachings in the story (independent variables). Our main findings included the existence of the cultural additivity of Confucian and Taoist values. More specifically, empirical results showed that the interaction or addition of the values of Taoism and Confucianism in folktales together helped predict whether the key message of a story was about Confucianism, β{VT⋅VC} = 0.86. Meanwhile, there was no such statistical tendency for Buddhism. The results lead to a number of important implications. First, this showed the dominance of Confucianism because the fact that Confucian and Taoist values appeared together in a story led to the story's key message dominated by Confucianism. Thus, it presented the evidence of Confucian dominance and against liberal interpretations of the concept of the Common Roots of Three Religions ("tam giáo đồng nguyên") as religious unification or unicity. Second, the concept of "cultural additivity" could help explain many interesting socio-cultural phenomena, namely the absence of religious intolerance and extremism in the Vietnamese society, outrageous cases of sophistry in education, the low productivity in creative endeavors like science and technology, the misleading branding strategy in business. We are aware that our results are only preliminary and more studies, both theoretical and empirical, must be carried out to give a full account of the explanatory reach of "cultural additivity".