The second type of social control we have studied consists of those structures and processes that bring the pressures of informal social interaction to bear on behalf of conformity or deviance. In this chapter, therefore, we inquire how scientific collaboration groups and other informal interaction structures may affect the “strict” and “permissive” patterns we have discerned among biomedical researchers. Here again we shall proceed by first reporting the methods and instruments we used to collect our data in this area. Then we shall suggest some of the ways that informal structures, just by themselves, may influence expressed standards and actual behavior in the use of human subjects. Finally, we shall suggest certain effects that informal interaction structures, in interaction with certain socialization patterns, may have on actual behavior as reported to us by our respondents. Informal colleague interaction, through the processes of collaboration, ethical consultation, and decision-making, has possible and actual effects on standards and behavior which we shall now seek to describe.