Social styles is one of many two-quadrant systems for explaining people's personalities and interactions. The unique perspective of this system is it is concerned with how other people perceive you. On one axis you are rated if you are concerned with people, or with tasks. On the other axis you are rated if you ask, or if you tell, when you want someone else to do something. No one social style is superior to another. The key to being effective is your ability to be flexible and work with the various social styles. Thus, style versatility is the second portion of the book.
I found this model very useful in all facets of my life. Where I work the dominant personality quadrant outnumbers the others 2:1 and determines the site's personality. We have a companion division with a different dominant personality - friction between the two sites on projects is just as the social styles predicts.
In my workplace this material is taught as Leadership Styles using materials Wilson Learning also prepared. The class to me presented the material much better than this book. The book is missing something - thus, minus a star.
Another book on the topic is "Personal Styles & Effective Performance" by
David W. Merrill and Roger H. Reid. According to my instructor, it is the original source which Wilson Learning and The Trane Co. created their respective training programs.