alter-egotism
/ˌaltə(r)ˈɛɡətɪz(ə)m/ /ˌɔːltə(r)ˈɛɡətɪz(ə)m/ /ˌɒltə(r)ˈɛɡətɪz(ə)m/noun
The identification of others with oneself; specifically (in later use) = alter-egoism.
Origin
Mid 19th century; earliest use found in Frederick Olmsted (1822–1903). From alter ego + -ism, with insertion of t after egotism.