My career-long goal to build a solid conceptual foundation for the study of these poorly understood interactions. Using a combination of field observations, experiments, and theory, the Bronstein lab is examining how population processes, abiotic conditions, and the community context determine net effects of interactions for each participant species. Specific conceptual areas of interest include: (i) conflicts of interest between mutualists and their consequences for the maintenance of beneficial outcomes; (ii) the causes and consequences of "cheating" within mutualism; (iii) context-dependent outcomes in both mutualisms and antagonisms; and (iv) anthropogenic threats to mutualisms. With colleagues, I am extending these concepts to explore business and educational “ecosystems”, as well as terrorist networks and how principles of ecosystem organization can be used to disrupt them.