How we change what others think, feel, believe and do
People have an external 'perceived locus of causality' (PLOC) to the extent they sees forces outside the self as initiating, pressuring, or coercing one’s action. In an internal PLOC a person feels they are the initiator and sustainer of their own actions.
People with a higher internal PLOC thus feel self-determined in that they see their behavior as stemming from their own choices, values, and interests, whereas those with an external PLOC experience their behavior as controlled by some external event, person, or force.
The internal locus is connected with intrinsic motivation, whilst the external locus is connected with extrinsic motivation.
The distinction between intrinsic and extrinsic is a core part of SDT, which was developed in the wake of Behavioralism and Conditioning, where behavior management is based around reward and punishment. SDT extends this extrinsic view to consider intrinsic effects.
There are three needs that SDT identifies as requiring satisfaction:
I feel in control of my own life. I feel responsible for my actions. I have a high internal locus and motivate myself. My friend is always complaining that they are being 'forced' to do things and that life is not fair. They have a high external locus and are more affected by reward and punishment.
Find out whether people have stronger internal or external locus and then persuade them accordingly. For internal locus, you might show how they are control and let them choose. For external locus you could show how they are being driven by outer forces and then offer a safe haven for them.
Understand your own PLOC and how you attribute cause. Think about whether this is effective for you and whether you want to change it. Also note how this relates to how others persuade you (and how you persuade yourself).