Since 1945 SLA research to some extent has lived its own ?internal? life. Thus the goal of SLA has been outlined as the description and explanation of L2 acquisition . In recent decades however a rather intense development of different ? often called sociocultural - research approaches to SLA can be observed. In this paper I will investigate some aspects of the development within SLA research and take a look at conceivably ?external? influences from other sciences such as linguistics, psychology, sociology, anthropology, ecology and learning theories on SLA. In the article I take the position that modern SLA theories already to a certain degree have been, however might further be far more enhanced by accepting the challenge of reflecting and rethinking own positions in relation to theoretical frameworks of other ?sciences?.