the psychologists who are administering the support group that calista attends are doing research to look at psychological traits for men and women in the disordered eating group. these psychologists are most likely to find

I believe the answer is: evidence of negative affect

evidence of negative affect in this context refers to how a person's tendency to do a certain bad behaviors would be influenced by the negative emotions that they constantly experienced in their life.  In eating disorders, those negative emotions could include things such as disgust, fear, anxiety, or guilt.