Section 6. The department shall be under the direction, supervision and control of the commissioner of children and families, in this chapter called the commissioner, who shall be appointed by the secretary of health and human services, with the approval of the governor, and who shall serve at the pleasure of the secretary, and may be removed by the secretary at any time, subject to the approval of the governor. Said commissioner shall be qualified by training and experience to perform the duties of the office and shall at the time of appointment have received a doctorate or other degree beyond the level of the baccalaureate in the field of business, economics, education, government, law, medicine, psychology, public administration, public health, public policy, social work, urban planning, or a field substantially related to one or more of the foregoing and shall have had not less than seven years of responsible administrative experience, at least three of which shall have been in a field related to human services, or said commissioner shall have had experience in one or more of said fields for a period of years equivalent to the number of years required to obtain such other degree beyond that of baccalaureate required herein, and shall have had, in addition thereto, not less than seven years of responsible administrative experience, at least three of which shall have been in a field related to human services. The position of commissioner shall be classified under section 45 of chapter 30 and the salary shall be determined under section 46C of said chapter 30 and the commissioner shall devote full time to the duties of the office. The commissioner shall be the executive and administrative head of the department.