The concept of relative deprivation was coined by an American sociologist, Stouffer. He discussed the concept in his book American Soldier.
The term relative deprivation means the feeling of disadvantage or deprivation experienced by an individual or a member of a social group when they compare their position with that of others.
Stouffer gives a good example of relative deprivation. He observed that married soldiers in the American army felt unhappy when they compared their conditions with that of unmarried soldiers. The unmarried soldiers did not have any responsibility as compared to married ones. The married soldiers are envious of the unmarried soldiers, especially of their freedom. The married soldiers also felt unhappy when they compared themselves with the married civilians of their country who were living happily with their families. The married soldiers thought that they were sacrificing the best part of their life, away from their near & dear.
To conclude, Stoffer points out that people often compare themselves with others who are more or less similarly placed. They do not compare with others who are markedly different.