What does scarcity thought mean?

Yesterday in the money course Jamie said that “fairness is a scarcity thought” and the woman she was talking to was really happy to know that. I am trying to understand what a scarcity versus abundance thought means in this context as it seemed so important. I have found nothing in the terms & concept workbook. Please elaborate so that is clear for us that have not taken that class or direct me to a certain class explaining it, please. Thank you in advance.