The educational concept of "Zone of Proximal Development", introduced by Vygotskij, stems from the identification of a strong need for adaptation of the learning activities, both traditional classroom and modern e-learning ones, to the present state of learner's knowledge and abilities. Furthermore, Vygotskij's educational model includes a strong bent towards social and collaborative learning. The joint answer to these two trends can be concretely implemented through a tight integration between personalized learning paths and collaborative learning activities. Along this line, the authors designed the combination of the functions of two pre-existing prototypes of web-based systems, to investigate how the above integration can merge adaptive and social e-learning. LECOMPS is a web-based e-learning environment for the automated construction of adaptive learning paths. SOCIALX is a web-based system for shared e-learning activities, which implements a reputation system to provide feedback to its participants. The authors propose a two-way tunneling strategy to integrate the above prototypes. The result is twofold: on the one hand the use of the student model supported by LECOMPS in an adaptive e-learning course is extended to support choosing exercise activities delivered through SOCIALX; on the other hand the reputation and the skills gained during social-collaborative activities are used to update the student model. Under the social perspective induced by the integration, the authors present a mapping between the student model and the definition of Vygotskij's Autonomous Problem Solving and Proximal Development regions, with the aim to provide the learner with better guidance, especially in the selection of available social learning activities.