Use a numbered list to display complete sentences or paragraphs in a series (e.g., itemized conclusions, steps in a procedure).
Use a lettered list or bulleted list rather than a numbered list if the items are phrases.
To create a numbered list, use the numbered list function of your word-processing program. This will automatically indent the list as well. Select the option for an Arabic numeral followed by a period but not enclosed in or followed by parentheses.
This is an example of a numbered list:
Our hypotheses were as follows:
- Social media use would be associated with lower mood.
- Active participation in social media would be associated with higher mood than passive participation.
- Perceived meaningfulness of online activity would mediate the relationship between online activity and mood.
Numbered lists are covered in Section 6.51 of the APA Publication Manual, Seventh Edition
This guidance is the same as in the 6th edition.
From the APA Style blog
Navigating the not-so-hidden treasures of the APA Style website
This post links directly to APA Style topics of interest that users may not even know exist on the website.