Etheredge (1978) proposed the importance of the traits; "dominance", "interpersonal trust", "self-esteem" and "introversion-extroversion", in leadership views and policy shaping. Etheredge found from studies on leaders during the Soviet Union, that those who scored highly on dominance were more likely to support the use of force during debate settlement. He found that the trait introversion can lead to a lack of co-operation, and that extroversion usually leads to cooperation and negotiation. Further he suggested that interpersonal trust and self-esteem were closely related to not advocating force.