They can be traded for material goods only because we all agree that they can and when someone moves their agreement, when people withdraw some number, people withdraw their agreement, those things no longer have value. Well, emotions are kind of built in the same way. Heart rates change, faces move, distress can occur out of loss when you lose someone who helps to regulate your body budget and you lose that person, you feel like you've lost a part of yourself because sort of you have actually lost someone who's helped you regulate