Columbia subject headings:
Intellect--History.
Nature and nurture.
People with mental disabilities--Education.
People with mental disabilities--Intelligence levels.
Harvard subject headings:
Intellect--History.
Nature and nurture.
People with mental disabilities--Education
People with mental disabilities--Intellectual levels.
Princeton subject headings:
Intellect--History.
Nature and nurture.
People with mental disabilities--Education.
People with mental disabilities--Intellectual levels.