Photoshop Elements suggests 3 methods of paragraph text alignment - "Left Align", "Center", and "Right Align".
The "Justify Paragraph" action adds the fourth - "Justify" - option.
- Create a text paragraph* (as opposed to "single-line" text**).
- In the Effects palette, double-click the "Justify Paragraph" pictogram (screenshot).
*To create "paragraph" text, drag on the image with the Type tool and then enter your text into the bounding box.
**To create "single-line" text, just click with the Type tool and start typing.