This work is based on a «re-assessment» of the Latin American experience regarding interventions in favour of a more harmonious territorial development. A retrospective view allows us to conclude that half a century of «trial and error» does not lead to a satisfactory result. The explanation favours a cognitive lack of the real structure and dynamics of the growth and development processes. Moreover, a new cognitive framework is suggested which is strongly based on the systems theory and on the evolving consequences of an increasing complexity.