«

»

Always use a person’s self-identified pronoun.

The singular “they” is a generic third-person singular pronoun in English. Use of the singular “they” is endorsed as part of APA Style because it is inclusive of all people and helps writers avoid making assumptions about gender. Although usage of the singular “they” was once discouraged in academic writing, many advocacy groups and publishers have accepted and endorsed it, including Merriam-Webster’s Dictionary.

[...]

APA Style and Grammar Guidelines: Singular "They"