Each time people come face to face with different situations, they interpret the same on the basis of their past experiences. Post evaluation of the situation, they choose their reactions.
Such reactions make people pick up and wear 'Masks' (read rationalized /projected behaviours) depending on what they believe is their influence & their control over the 'Surrounding Factors'.
The people around them experience & react to the moderated & rationalized ('Masked') behaviours they experience . Reciprocally, they likewise pick up their own Masks to wear.. and the trail chain of 'Masked' behaviours thus gets triggered-off.
Each one of us consciously and sub-consciously, influences & affects others in some way or the other. Success in such a complex web of behaviours is an outcome of closely observing past and present behaviours of people on the one hand AND unraveling discreetly, the hidden ('under the surface') behaviours of people, on the other hand.
Read the doodle reflecting the 'behavioural' mathematical formula suggested by Thomas Erikson : Behaviour = f( P x Sf ). Behaviour is a function of Personality and the influencable Surrounding Factors.
Unless people master the art of understanding the web of human behaviours in groups, their ability to succeed as leaders will be impaired.