Figure 1. Item probability plot for final four class solution of co-use motives.

Note: Slight changes to wording in the figure were made for space. In the survey, “Makes experiences/activities more fun” was presented as “Makes experiences/activities more fun or interesting,” “Experimentation” was presented as “Experimentation (e.g., new experience, curiosity),” “Helps me cut down or use less” was presented as “Helps me cut down or use less of one or both substances” and “Easier to hide my use from others” was presented as “Easier to hide my use from others (use discretely).”