The correct answer is because it refers to beliefs or emotions.
Are you offered any option? I can tell you that the main goals of psychology research are to describe, predict, explain, and control human behavior. I hope this helps you finding your answer.
According to Greenleaf's definition, we can understand that servant leadership imposes that leaders must first be concerned with the well-being and success of their followers, and then establish their leadership principles. Greenleaf believes that the leader who fits this concept is more likely to be successful and to get to know his team's work in depth, being able to predict possible problems and solutions more easily.
On the one hand, Greenleaf is correct, because his arguments present the strengths of this type of leadership. In addition, servant leadership brings leaders and collaborators closer together and strengthens trust between them. However, this type of leadership can present negative points as well, such as the lack of authority and respect that this leader acquires. In this way, employees can see the leader as an equal and not as someone to be followed.
It must be observable. People who agree with the Big Bang theory say that things such as stars and galaxies moving away from a center is proof. However, no one can test the Big Bang.