Final answer:
The quote is attributed to George Herbert Mead who studied the self and identity within the field of sociology.
Step-by-step explanation:
The quote "Identity is what the core of one's allegiance makes one to be" is attributed to George Herbert Mead. Mead was a philosopher and sociologist known for his work on the development of the mind and self through social interaction—in fact, he's one of the foundational thinkers in the field of sociology. His theory emphasizes that identity is constructed based on how an individual perceives others seeing them, which then informs their self-awareness and social behaviors.