Reciprocal, mutual, common mean shared, experienced, or shown by each of the persons or things concerned.
Reciprocal has for its distinctive implication the return in due measure by each of two sides of whatever is offered, given, or manifested by the other.
Usually therefore it implies not only a quid pro quo but an equivalence in value, though not necessarily in kind, on each side (as of love, hate, understanding, courtesies, concessions, or duties).
Mutual is often used in place of reciprocal when the idea of return or interchange is suggested and that of sharing equally or jointly is stressed.
But mutual is applicable, as reciprocal is not, to two persons who entertain reciprocal feelings toward each other.
When there is little or no suggestion of a reciprocal relation (as between thoughts or feelings) and the emphasis is upon the fact that the two persons or things involved entertain the same feelings towards each other, perform the same actions, or suffer the same results, mutual is more appropriate than reciprocal .
Both reciprocal and mutual are sometimes used when more than two persons, classes, or things are involved, but when there is no implication of reciprocity, common is the more usual term; thus, one says “we (two, three, or more persons) are mutual friends,” meaning that all are friends each of the other but “they have common friends,” meaning that each has friends who also are friends of the others; the members of a group may have a common purpose.
Common (see also COMMON 3 ); (see also UNIVERSAL 2 ) implies joint participation or possession by two or more persons, and differs from mutual in not being restricted as to the number involved and in not carrying a suggestion of a reciprocal relation or of an equivalence of feeling, performance, or effort.