psychologist
A professional who studies psychology or provides psychological counseling.
She works at a hospital as a clinical psychologist.
Psychologists study human behavior.
A psychiatrist (medical doctor who can prescribe medication), while 心理学者 is a psychologist (focuses on therapy and research, not a medical doctor).
A counselor (often provides guidance or therapy), but 心理学者 is more academic/research-oriented or a licensed clinical psychologist.
child psychologist
Compound of 心理 (psychology) + 学者 (scholar, -ologist).