More importantly, the acceleration of Chinese immigration from the late 19th century had produced a situation in which by 1930 a majority if the Indonesian Chinese were either first or second generation immigrants. Moreover, the very scale of this immigration during this period, coupled with several other new developments in the early 20th century, was inhibiting the further acculturation of the Chinese. In particular, the population of women among the new immigrants was rising, so that there were now many families in which both parents were fostered amongst the immigrants and their children through the establishment of Chinese-language schools and a Chinese-language press. Thus at the very time when national consciousness was emerging amongst the Indonesian population, the Chinese minority was becoming more aware and proud of its Chineseness. This process made some headway even amongst the peranakan Chinese, some of whom sent their children to Chinese-language schools and became vociferous exponents of Chinese nationalism. In the early 20th century, therefore, the Chinese population was becoming increasingly 'Chinese' and, in the eyes of the Indonesians, 'alien', despite the considerable acculturation which had occurred earlier.
It has often been remarked that one aspect of indigenous culture to which the Chinese for the most part have remained impervious throughout their history of settlement in Indonesia has been the Muslim religion. Though not, of course, indigenous to Indonesia, Islam has been adopted as the religion of an overwhelming majority of the Indonesian population. Nevertheless, although so large a proportion of the Chinese have acculturated extensively in other ways, very few in modern times at least have been Muslims. Various reasons have been suggested for their reluctance to embrace Islam. For example, conversation to Islam is said to demand certain physical sacrifices form a Chinese settler, such as circumcision and abstinence from eating pork (a favorite Chinese dish). Furthermore the relative intolerance and exclusiveness of Islam (as compared with the tolerance and permissiveness of Theravada Buddhism in Thailand) have been said to be a barrier to the conversion of the Chinese, whose religious temperament is said to be 'eclectic and synergetic rather than exclusivist'. On the other hand, it is said that in Java the Chinese had no need to convert to Islam because of the presence of a large only nominally Muslim group amongst the Javanese (the abangan) from which they could wives whose religious demands were minimal. Finally, it is suggested that because the stricter Muslims (santri) included most of their Javanese trading competitors, who were of relatively low social status, whereas the abangan group included the traditional Javanese elite, the Chinese therefore regarded the Muslim religion as culturally inferior.