This paper summarizes the analysis of a male fraternal twin. The outstanding psychological peculiarities connected with the patient's twinship were the following: (1) a struggle between his unique inherited potentialities and an environment that accentuated his twinship; (2) a closely related conflict (not necessarily related to inherited differences however) between individuality (separate ego) and fusion with the twin (joint ego); (3) a secondary struggle, arising from the first two sets of conflicts, to obtain love and approval from the parents, at times by conforming to the twinship pattern, but at other times by being different from the twin; and (4) another secondary struggle to avoid the anxiety arising from his own hostilities in case the twin excelled and was preferred, or arising from the twin's hostilities in case he (the patient) excelled and was preferred, anxieties that could best be avoided if the patient became as much like his twin as possible.

Author's Summary.