Through a case study focusing on the Rio Ilave, Lake Titicaca Basin, Peru, this paper examines the Mid-Late Holocene climatic transition and the Archaic-Formative cultural transition as a means to evaluate two seemingly competing socio-natural theories for accelerated cultural change: resource stress and abundance. Stress based approaches emphasize the principle that experimentation, that may lead to behavioral adaptations, arises out of attempts to solve specific problems. Alternatively, abundance based approaches assert that rates of cultural change accelerate when material constraints or limits are eased. Results from the present case study indicate that during the relatively resource stressed arid Mid-Holocene, several new cultural practices developed: reduced residential mobility, storage, domestication, and intensified plant processing. During the succeeding moist and relatively resource abundant Late-Holocene, these new cultural practices greatly intensified. These intensified economic activities resulted in deforestation, and this in turn created new forms of environmental stress. Thus, experimentation occurred during a period of stress. This was followed by a relaxation of material constraints that led to intensification of the new economic activities. This intensification in turn appears to have generated new kinds of stress. This case study shows that, rather than forming competing theories, stress and abundance approaches explain different kinds and contexts of accelerated cultural change.