Student-to-student discussions enable peer learning even outside of the classroom.
But if you want to switch off student to student discussions in the courses, follow the steps mentioned below:
Select the Courses/Batches section from the home screen of the particular organization.
Select the particular course.
Click on the Manage option and select Course Settings.
Under the learner's view section, the learner to learn discussions can be switched off by unmarking the checkbox against the Enable learner to learner discussions.