Take your time. In order to make generalizations about society as a whole, cross societal research must be done. Objectivity, impartiallity, and emotional reasoning are all parts of intellectual honesty. Christopher Colombus discovered the earth is round. Through the scientific method a theory is proven or disproven.
Words are symbols for concepts.
A theory is a directly testable statement. Sociology is the study of human social behavior. A variable is anything that changes. It is sociology's job to prove what we know is common sense. Correlation implies causation.