Final answer:
Gender identity is a person's perception of the self as female or male, typically established between eighteen months and three years of age. It refers to one's sense of being male, female, neither of these, both of these, or another gender.
Step-by-step explanation:
Gender identity is a person's perception of the self as female or male. Typically established between eighteen months and three years of age, it is a powerful aspect of our self-concept. Gender identity refers to one's sense of being male, female, neither of these, both of these, or another gender. Transgender people's gender identity differs from the sex they were assigned at birth.