The present invention concerns a controlled structure copolymer comprising at least two different parts, a first part A, amphoteric or zwitterionic, including anionic or potentially anionic units, and cationic or potentially cationic units, or zwitterionic units, and another part B, non amphoteric or zwitterionic. Said copolymer further exhibits a high potential for adaptation, through variation in its composition, in order to improve or modify the properties of compositions in which it is introduced.