- A difficult but important task of archaeology is to answer the question "why" and indeed much of archaeology has focused on the investigation of why things change. Before the 1960s changes in material and social culture were explained by migration and cultural diffusion.
- The processual approach of New Archaeology, which began to take hold in the 1960s, attempted to isolate the different processes at work within a society. Rather than placing an emphasis on movements of people as the primary cause of change and development, early processual archaeologists looked more to humanity’s relationship with its environment, on subsistence and economy, and the other processes at work within a society to explain why a society was how it was.
- Processual archaeology often addresses big questions such as the rise of agriculture and the origins of the state. In general, multivariate (several factor) explanations are better than monocausal (single factor) ones.
- Marxist archaeology, focusing on the effects of class struggle within a society, does not contradict the ideas of processual archaeology, and nor does evolutionary archaeology, which is centered on the idea that the processes responsible for biological evolution also drive culture change.
- As a reaction to the "functionalist" approach of early processual archaeology, so-called postprocessual approaches developed in the 1980s and 1990s, emphasizing the subjectivity of archaeological interpretations and drawing on structuralist thinking and neo-Marxist analysis.
- New cognitive-processual approaches in the 1990s sought to overcome some of the limitations of early processual archaeology. A greater emphasis is placed on the concepts and beliefs of past societies, and the difficulty of testing hypotheses concerning culture change is recognized.
- One aim of contemporary archaeology is to keep track of the individual in explaining change. Agency, defined as the short-term intentionality of an individual, may indeed have long-term and unforeseen consequences that lead to cultural change. Another aim is to recognize the active role of material culture in the way humans engage with the world.
Migrationist and Diffusionist Explanations
The Processual Approach
Processual (New) archaeology, pp.481, 483
Functional-processual approach, p.485
Cognitive-processual approach, p.485
Marxist archaeology, p.486
Human behavioral ecology, p.487
Richard Dawkins, p.487
The Form of Explanation: General or Particular
Natural laws, p.489
Deductive-nomothetic explanation, p.490
Hypothetico-deductive explanation, p.490
Monocausal explanation, p.491
Hydraulic hypothesis, p.491
Environmental circumscription, pp.492, 494
Multivariate explanation, p.494
Systems approach, p.494
Negative feedback, p.494
Postprocessual or Interpretive Explanation
Structuralist approaches, p.499
Critical Theory, p.499
Cognitive-processual archaeology, pp.501–03
Agency and Material Engagement
Material engagement, p.504