This new system created even more divisions in Angolan society by separating the population into groups, which actively competed with one another. The old Afro-Portuguese families, who often identified economically and culturally with the white settlers, saw their historical privileges taken away and became increasingly critical of the colonial government and at odds with white settlers. Mestiços also felt threatened by the newly educated class of Africans, who were seen as usurping their traditional roles in the colonial hierarchy. This split within the assimilado group carried on through the civil war, with the MPLA leadership coming mostly from the older established group, and the leaders of FNLA and UNITA from the newer group.   
Besides the divisions among assimilados, there was also significant tension between assimilado and indígena populations. When they went through the process of assimilation, assimilados made a conscious decision to completely abandon their African heritage and adopt European culture. This process detached the assimilados from the largely rural, uneducated indígenas and often made it difficult for the two groups to see eye-to-eye and identify with one another. Though Africans continued to enter the assimilado class, the stringent restrictions on assimilation and the reluctance of many Africans to give up their African culture meant that less than 1% of Angola’s population was ever formally assimilated. 
In the post-WWII period white immigration to Angola reached new highs as industrialization brought about massive rural unemployment in Portugal. Immigration to Africa was seen as both a solution to Portugal’s excess population problem and as a way to strengthen Portuguese control over its colonies. With the white population in Angola increasing from 44,000 in 1940 to 325,000 in 1974, Europeans soon took over not only upper and mid-level positions, but also most low-wage jobs in the city, displacing most of the urban African population. Having lost much of their status to poor white settlers, mestiço and assimilado populations felt increasingly marginalized by the Portuguese, and members of these groups would form the leadership of most of the independence movements in the 1950s and 60s. In addition to the social-cultural hierarchy imposed by the Portuguese, ethnic divisions were also intensified by other colonial policies.
The effects of the plantation system in the early twentieth century also exacerbated tensions between African ethnic groups. In the northern part of the country, large numbers of peasants were displaced to make room for commercial coffee plantations. Many of these farmers, mostly Kikongo-speaking members of the Bakongo ethnic group, fled to neighboring Zaire, where they flourished as small-scale commercial coffee farmers. As successful small entrepreneurs, many of the Bakongo diaspora in Zaire would be wary of the socialist policies of the MPLA, and would instead choose to support the ostensibly more business-friendly FNLA, which was also led by Bakongo and based in Zaire. After living in francophone Zaire for several generations, most of the Bakongo refugees adopted French, further dividing them from the mostly Portuguese-speaking groups in Angola.
