Armrest and seat arrangement comprising the same

For enabling a seat arrangement having more seats in a given space for a row, the invention proposes an armrest (24) for arrangement between two seats (20, 22), especially two passenger seats of a vehicle such as an aircraft (12), comprising at least one first support portion (34) for an arm (35) of a first person and at least one second support portion (36) for an arm (38) of a second person wherein the first and second support portions (34, 36) provide different height levels (44, 46).