The participation of other people might dilute the effect of feeling connected through the more specific, interdependent experience (like half half) you had with specific people.
If the half half experience used callbacks to create needs with situation number = 2, then we could just grab the needs you participated in. The API model is currently broken specifying 50 people for a half half experience, when really its 2 that you need for the half. (Too much logic is being handled by the front end template)