A brief note to say that descriptions of the Three Social Motives are now on my website (http://www.motivateyourwriting.com/motivations.htm). These came from the patterns of thoughts displayed by people, so what you are seeing there are the expressed thoughts of someone relatively strong in one motive versus another.
1. You have all three, but to different degrees
2. There are more than three, but these account for most daily thinking (80-85%)
3. These are thoughts, not behaviors!
A comment on each of my comments!
You have all three
Everyone has all three motives, but most people have one that is significantly stronger than the other two. If you think of motives as rolling (six-sided) dice (3d6, for gamers), it is more likely for you to have only one six than three! Most people have one relatively strong, a smaller number of people have two, and a smaller number still have all three significantly above the mean. That's leaving out degree of strength (you can have a strong or a STRONG motive), but that's another story.
There are more than three, but these account for most daily thinking
Henry Murray came up with a list of fifty or more motives (at some point I'll list them). However, David McClelland cleverly figured out that not all of them applied often, so why not focus on the most important? This led to the Three Social Motives. The reason we know about the percentage of time is due to a neat study designed by Carol Constantian. which used a beeper to track people's thinking. She would beep them at random intervals, and they would write down whatever they happened to be thinking about. Please note that if you are strong in one motive, you are more likely to be thinking about Achievement, for example, than the other two. And of course there are always exceptions, which is part of what makes psychology fun. Or not.
These are thoughts, not behaviors!
David Winter, the guru of Power motive, found that people with high Power/Influence motive admitted to more thoughts about violence, but those that did were in fact the more mature people! So if you are consciously able to address those thoughts, you are less likely to actually do the behaviors. This may explain a lot about why mystery writers are such civilized people overall--they kill a lot of people in their fiction!
Obviously thoughts lead to behaviors, but not one-to-one. The same thought can lead to multiple behaviors, and different thoughts can lead to the same behaviors. For example, take someone who stutters. If that person has a strong Power/Influence motive, that person may feel uncomfortable speaking in public and become a writer to express his or her thoughts. On the other hand, that same person could decide that having direct impact is more important, and learn to overcome the stutter. Power motivation motivates both sets of actions! Motivation alone is not enough to explain behaviors. It is fed through other thoughts, which is why I referred to levels of motivation last post. What these motives do do is lead to a pattern of behaviors over time, but which one is up to you and your values and/or skills. More on that another time...
A beeper study:
McAdams, D.P., & Constantian,C.A. (1983). Intimacy and affiliation motives in daily living: An experience sampling analysis. Journal of Personality and Social Psychology, 45, 851-861.