This is an author post-print (ie final draft post-refereeing) of the paper published in Scientometrics, 72, 1 (2007): 59-80. The original publication is available at www.springerlink.com [http://www.springerlink.com/content/d700kh1418462720/?p=e41b56707b6140f08e3188801cb1187b&pi=4]The aim of this paper is to explore to what extent social integration influences scientists’ research activity and performance. Data were obtained from a survey of researchers ascribed to the Biology and Biomedicine area of the Spanish Council for Scientific Research, as well as from their curricula vitae. The results provide empirical evidence that researchers who were highly integrated within their teams performed better than their less integrated colleagues in aspects of research activity such as collaboration with the private sector, patenting, participation in domestic funded research and development projects, and supervision of doctoral dissertations. Nevertheless, highly integrated researchers did not seem to be more prestigious than less integrated colleagues, nor did the former’s publications have a higher impact.El objetivo de este trabajo es investigar hasta qué punto la integración social influye en la actividad investigadora y el rendimiento de los científicos. Los datos del estudio proceden de una encuesta a los investigadores adscritos al área de Biología y Biomedicina del Consejo Superior de Investigaciones Científicas, así como de su currículum vite. Los datos señalan que los investigadores bien integrados en el seno de sus equipos tuvieron un mayor rendimiento que sus colegas menos integrados, en distintos aspectos de su actividad investigadora, como la colaboración con el sector privado, la actividad patentadota, la participación en proyectos de I+D financiados en convocatorias nacionales, y la dirección de tesis doctorales. Por el contrario, no se encontraron diferencias en los indicadores de prestigio de los científicos, ni tampoco en el impacto de las publicaciones.The research reported in this paper was done as part of the ‘Consolidation and cohesion of CSIC research teams and their influence on the research activity and performance of their components’ research project (CSIC intramural project 200410E051)Peer reviewed