There are several ways to combine other interests with computer science.
Even if you are in an Honors program, a significant portion of your coursework is purely elective, meaning available for whatever courses you choose (rather than dedicated to CS or General Education requirements). Take interesting courses—that’s what college is for! Not all your interests need to be reflected in your official degree program.
A lightweight way of getting official recognition within Harvard for work in two fields is to do one or the other as a secondary field. This generally involves taking 4 or 5 courses in the secondary field. Secondary fields appear on your transcript, but not your diploma.
Students with serious interests in both computer science and a related concentration—one that is either foundational to the study of computing, or where computing is being applied in significant ways—may pursue a joint concentration between the two. This is not a “double major”: the two fields must overlap, and the student must write a senior thesis acceptable to both concentrations. Computer science has had successful joint concentrators with engineering, social sciences, natural sciences, and the humanities.
Compared to the basic CS track, joint concentrators may take fewer Core Computer Science classes, and may use CS 91r to satisfy some CS requirements, but must write a thesis.
Students are responsible for ensuring that their degree program meets all deadlines and requirements of both concentrations. CS allows courses to count towards the requirements of both concentrations, but some other concentrations do not. We advise all our joint concentrators to satisfy the basic requirements for at least one of their concentrations, in case they do not complete a thesis. Students considering a joint concentration should consult the DUS team early to plan their courses, and consider whether a secondary field or elective would better meet their needs.
Joint concentrations are honors-track programs. Each field recommends honors separately, and in most circumstances the minimum recommendation takes precedence. The primary field (the first-listed concentration) is ultimately responsible for the English honors recommendation, however.
Students interested in addressing questions of neuroscience and cognition from the perspective of computer science may pursue a special program of study affiliated with the University-wide Mind, Brain, and Behavior Initiative. This honors-track program allows students to participate in a variety of related activities. Similar programs are available through the Anthropology, History and Science, Human Evolutionary Biology, Linguistics, Neurooscience, Philosophy, and Psychology concentrations.
If you want to study hardware (e.g., chips, circuits, and memory) as well as software, consider pursuing the Electrical and Computer Engineering track as part of the Engineering Sciences concentration. This is distinct from, but parallel to, the Computer Science concentration.
The Peer Concentration Advisors have compiled the CS Interdisciplinary Paths Unofficial Guide, a resource that contains further advice on combining computer science with other fields, including sample plans of study and specific courses that may be of interest.