Headings and the Use of Boldface Type
APA has gotten a lot of questions and feedback from users who are confused about when to use boldface type and when not to, particularly in headings. Here are the short and sweet answers about font formatting style:
Use regular font formatting (no boldface, no italics) for all section titles, such as
- Author Note,
- Title of Your Paper (on the title page and on the page where the text begins),
- Appendix/Appendices, and
Section titles should also be centered, on their own line, and in title case (that means capitalize all major words—for more information what words are considered major, see the first bullet in Section 4.15 on p. 101 of the Publication Manual). A section also generally begins on a new page. (The only exception is for the author note section, which goes on the title page.)
Use boldface only for headings within the body of your paper, that is, within the text itself—these headings we refer to by levels (Levels 1–3 use boldface; Level 4 uses boldface and italic; Level 5 uses italics only). This blog on headings describes the levels in more detail (see also Section 3.03 on pp. 62–63). Common headings within the body of the paper are Method, Results, and Discussion, but your headings will differ depending on what you are writing about. Additionally, if you have an appendix with lots of text, you can use the levels of heading within that body of text as well (but the section title "Appendix" would still use regular nonboldface formatting).
Take a look at the sample papers for examples of how section titles use regular formatting and headings within the body of the paper use boldface.