The theory of psychological egoism suggests that no act of sharing, helping, or sacrificing can be truly altruistic, as the actor may receive an intrinsic reward in the form of personal gratification.
ðə θˈiəɹi ʌv saɪkəlˈɑːdʒɪkəl ˈiːɡoʊˌɪzəm sədʒˈɛsts ðæt nˈoʊ ˈækt ʌv ʃˈɛɹɪŋ, hˈɛlpɪŋ, ɔːɹ sˈækɹᵻfˌaɪsɪŋ kæn biː tɹˈuːli ˌɔːltɹuːˈɪstɪk, æz ðɪ ˈæktɚ mˈeɪ ɹᵻsˈiːv ɐn ɪntɹˈɪnsɪk ɹᵻwˈɔːɹd ɪnðə fˈɔːɹm ʌv pˈɜːsənəl ɡɹˌæɾɪfɪkˈeɪʃən.