When you are looking at group position you are looking at the study of prejudice. Prejudice is when we have a negative view of an individual due soley on our perception of their racial group. This includes have predetermined beliefs about attributes of the group as a whole and the behaviors of the person as an individual that our affected by our beliefs of this racial group. The group theory looks at how a relationships between different racial groups, and the social "pecking order" of the racial groups, affect the persception we may have about other racial groups. For example if Group A is the dominate racial group in terms of financial ability and influence within the community, Group B has the next level of financial ability but less influence, and Group C has the lowest level of financial ability and no influence group position theory will look at how members of each group percieve each other.
Historically, social dominance has been a part of society for many years. Jim Sidanius and Felicia Pratto, co-authored a book entitled Social Dominance : An Intergroup Theory of Social Hierarchy and Oppression which discusses the different groups and their behaviors. It also specifies names of each group and their purpose and the factors that give rise to their behaviors such as gender, race, class, economic and age discrimination. They also define different theories that have been in existence for decades.
The authors define group position in a category of Social-Structural and Elite Theories which states that because of a state of inequality or power, the more powerful groups attempt to hold their position over groups that are less powerful. The powerful groups accomplish this by promoting social attitudes and policies that are advantageous to them.