Consider being in a class full of 30 students including yourself. You all take an exam and get a grade back. Technically, you achieved an A, however, the class is socialist and so an average of the results of the whole class is taken. You then end up with a B. The capitalist class next door would have let you take your A and be done with it.
This is an awful analogy that doesn't have anything to do with socialism. "To each according to his contribution" is a core aspect of it which grants a larger portion of social output to those who are the most productive and technically knowledgeable in their field, while giving little to those who contribute less. And hierarchies are only established based on your skills and expertise.