Social things are transactional, they facilitate exchanges among those who encounter them. Using the research that you have done on a tribe, you will start designing a tangible or a wearable object for or with that tribe.
The goal is to create a meaningful object using physical computing as an agency. By meaningful, we mean that it will communicate the value(s) of your tribe.
Your object may be a social lubricant, socialising the autonomic, protect aloneness, allow remote presence, to expand / restrict participation or debate.