Mass. Gen. Laws ch. 13, § 64

There shall be a board of registration of chiropractors, in this section and in sections sixty-five and sixty-six called the board, consisting of seven members to be appointed by the governor, who shall be residents of the commonwealth, six of whom shall be registered chiropractors, and one of whom shall be a representative of the public, subject to the provisions of section nine B. Upon the expiration of the term of any member of the board, his successor shall be appointed in like manner for a term of three years. No more than a majority of the board shall be graduates of the same legally chartered chiropractic school or college.