Why must political science be studied with other sciences and disciplines?

Social systems, like politics, are influenced and influence many other elements of society (e.g.) economics, psychology, anthropology, sociology, et al.), natural sciences (e.g.) Biology, medical science, engineering, administration, et al.), and humanities (e.g.) history, literature, philosophy, et al.) so it is difficult to understand political science in isolation from these other fields. To some degree, understanding political science depends on understanding these studies as well.