A composition comprising (1) a first crosslinkable polymer compound having an aromatic conjugated repeating unit and a crosslinkable group and having at least one of a light emitting property and charge transportability, and (2) a second crosslinkable polymer compound having an aromatic conjugated repeating unit and a crosslinkable group at least one of which is different from the aromatic conjugated repeating unit in the first crosslinkable polymer compound and the crosslinkable group in the first crosslinkable polymer compound, and having at least one of a light emitting property and charge transportability, wherein at least one of the first crosslinkable polymer compound and the second crosslinkable polymer compound has a crosslinkable group represented by the following formula (Z-3) or (Z-4): in the formulae, Rc represents a hydrogen atom, or a substituent such as an unsubstituted or substituted alkyl group or the like, the plurality of Rc moieties may be the same or different.