Unilineal Cultural Evolution Theory was a popular nineteenth-century theory of social organization. Essentially, this theory argued that all humans developed in a similar way, and that there was a universal order that cultural evolution adhered to. The theory also classified cultural differences according to technological development and the intricacy of social organizations. For example, a society that did not have a great deal of advanced technology would be considered “savage” according to this theory. Key anthropologists who were associated with this theory were Edward Burnett Taylor and Lewis Henry Morgan. This theory was important in how it theorized a new way of looking at societies. Critics, many of whom were historical particularists, argued that it is not possible to gather enough evidence to prove cultural labels like inferior and superior. Many felt this theory failed to take into account important sociocultural context and was thus too simple. This theory has also been critiqued for reflecting racist ideologies of cultural superiority.
Historical particularism is different from the Unilineal Cultural Evolution Theory because it argues that cultural development must be understood in the particular context of each culture. It is similar to Unilineal Evolution Theory in that it does not suggest that there is no potential for universal patterns of development. However, it emphasizes the importance of more in-depth ethnographic research to examine how specific environmental and historical factors impact a culture’s development. A key anthropologist associated with this theory was Franz Boas.