(sensing–judging) Myers–Briggs types, the Guardian temperament comprises the following role variants (listed with their correlating Myers–Briggs types): Inspector (ISTJ), Protector (ISFJ), Provider (ESFJ), and Supervisor (ESTJ). Guardians are concrete and organized (scheduled). Seeking security and belonging, they are concerned with responsibility and duty. Their greatest strength is logistics. They excel at organizing, facilitating, checking, and supporting. The two roles are as follows: Administrators are the directive (proactive) Guardians. Their most developed intelligence operation is regulating. The attentive Inspectors and the expressive Supervisors are the two role variants. Conservators are the informative (reactive) Guardians. Their most developed intelligence operation is supporting. The attentive Protectors and the expressive Providers are the two role variants. Idealist The Idealist temperament is one of four temperaments defined by Keirsey. Correlating with the NF (intuitive–feeling) Myers-Briggs types, the Idealist temperament comprises the following role variants (listed with their correlating Myers-Briggs types): Champion (ENFP), Counselor (INFJ), Healer (INFP), and Teacher (ENFJ). Idealists are abstract and compassionate. Seeking meaning and significance, they are concerned with personal growth and finding their own unique identity. Their greatest strength is diplomacy. They excel at clarifying, individualizing, unifying, and inspiring. The two roles are as follows: Mentors are the directive (proactive) Idealists. Their most developed intelligence operation is developing. The attentive Counselors and the expressive Teachers are the two role variants. Advocates are the informative (reactive) Idealists. Their most developed intelligence operation is mediating. The attentive Healers and the expressive Champions are the two role variants. Rational The Rational temperament is one of the four temperaments defined by Keirsey. Correlating with the NT (intuitive–thinking) Myers-Briggs types, the Rational temperament comprises the following role variants (listed with their correlated Myers-Briggs types): Architect (INTP), Fieldmarshal (ENTJ), Inventor (ENTP), and Mastermind (INTJ). Rationals are abstract and objective. Seeking mastery and self-control, they are concerned with their own knowledge and competence. Their greatest strength is strategy. They excel in any kind of logical investigation such as engineering, conceptualizing, theorizing, and coordinating. The two roles are as follows: Coordinators are the directive (proactive) Rationals. Their most developed intelligence operation is arranging. The attentive Masterminds and the expressive Fieldmarshals are the two role variants. Engineers are the informative (reactive) Rationals. Their most developed intelligence operation is constructing. The attentive Architects and the expressive Inventors are the two role variants. Four interaction roles In his book Brains and Careers (2008), Keirsey divided the role variants into groupings that he