Answer:
Being the Grunt has caused Eric to have a negative opinion of himself, since he is constantly given the least desirable tasks and not given recognition for his hard work. This lack of recognition and appreciation has caused Eric to feel devalued and has had a negative effect on his self-worth.
My own experiences of being treated poorly by others have had a similar effect on my self-worth. I have felt devalued and unappreciated, which has caused me to doubt my abilities and to feel inadequate. These experiences have made me feel as though I am not worthy of respect and have made me feel less confident in myself.