• You cannot out-manipulate a skilled manipulator, so don’t even try.
• It’s useless to ask a manipulator why he or she is acting a particular way, because you won’t get an honest answer. Manipulators will deflect or disguise their motives and avidly deny being a manipulator. But take comfort in this: However how hard they try to convince you otherwise, you are not wrong for perceiving that you’re being manipulated.
• You can’t change a manipulator by pointing out that his or her approach is one-sided.
• Most manipulators are incapable of empathy. Therefore, trying to get them to understand your point of view is pretty much a waste of time.

- An abbreviated list from work of the late Harriet Braiker, author of “Who’s Pulling Your Strings”, from “Stand your ground with manipulators” at management-issues.com

This is encouraging to read, because I’ve spent a lot of my life trying to reason with manipulators; for example being invited to justify my choices, feelings or identity which is in reality an invitation to engage in being persuaded I am wrong.

Here’s some more, from “How To Spot a Manipulator” at ehow.com:

1. Explore your feelings. Think about how you feel after spending time with the people in your life. Perhaps dealing with someone close to you regularly leaves you feeling exhausted, depressed, fearful, lonely, guilty or worthless. If so, chances are that you have spotted a manipulator.
2. Spot manipulative tools. Manipulative behavior is by definition controlling and self-serving. Although some manipulators can be physically abusive, the real control usually is psychological. Manipulators have methods to delve deep inside your head and heart. They then push your buttons so that they can bend you to their will. Manipulators often use guilt or feign helplessness to persuade you to something for them. They may blame you unfairly, mock you or put you down. He or she may also demonstrate behavior that seems on the surface more positive, like using flattery and charm and professing love and caring.
3. See whether the manipulator alternates between flattery and affection and anger depending on whether you are accommodating his requests. The display of anger may be intimidating or passive-aggressive.
4. Determine whether the person uses your relationship with him to persuade you to do or not do things. Manipulators often make requests or demands by playing on your affections and your guilt. Spot manipulative comments like “If you loved me, you would (or wouldn’t) do this” or the converse: “Since you insist on doing this, I can no longer love or trust you.” There are no gray areas with manipulators. If you don’t perform as they wish, there is something lacking in you.
5. Analyze the reasoning the manipulator uses to get what he or she wants from you. Manipulators usually rely on irrational, emotional means of persuasion rather than logic to get their way.
6. Notice how the person acts when you change the way you respond to the manipulative behavior. Argue back, with logic. Do not humor the manipulator. Take your time answering and responding. Don’t take the bait. Be alert and prepared for changes in tactics, since the manipulator is highly invested in control and will try different strategies.