This is my point: to achieve anything you want to accomplish in life, you will have to deal with other people. So it makes logical sense to try to figure out how other people function, what the motivations behind their actions are and what their behavior signifies. This is the study of Psychology!
Unavoidably, we will all be faced a situation where we want somebody to do something that benefits us. But a problem that I see with a lot of people is that they fail to put themselves in their target's shoes. They try to force, or coerce their target into doing something, without giving thought to the other person's motivations or desires.
In my opinion, it takes a lot of energy to coerce somebody to do something against their will. It's analogous to trying to bang in a screw with a hammer. It's doable, but you'd be fucking retarded if you were to try building an entire house that way. You can usually see personal level coercion when people yell, use threats and hurl insults. Your typical inept mother howling at her children in the Shoppers Drug Mart is what comes to mind. Or perhaps the United States posing sanctions on Iran? We've all been guilty of this primitive form of social control at some point in our lives. Any intelligent person should seek to minimize instances where it is used.
A better way, I think, is to put your precious energy into getting the person to actually want to do what you want them to do. Your target is an individual, just like you, and will not do anything unless it benefits him/her in some way, just like you. Find a way to make what you want your target to do mutually beneficial. Both parties must derive some clear benefit, but this does not mean that you cannot benefit more than your target. Avoid the winner/loser bifurcation. Avoid making your target act in ways that are detrimental to his/herself (unless of course you are at war, in which case a whole different set of rules applies).
To summarize: make the people around you benefit from your presence, and they will actually want to help you achieve what you want to achieve. It's simple to do in theory, but very hard to do in practice! Next time you find yourself stuck dealing with an asshole/jerk/bitch/cunt, try a different approach than simple-minded coercion. Use a little finesse!