Chickens, and most all birds, are naturally frightened by things that are above them - this is why bird cages are usually hung high (and chicks will hunker down when a big bird flies over). I found my chicks were frightened of me the entire time they were in their brooder. What I did everyday, however, was to open the door and sit quietly holding out my hands with some treats on them. (They loved smushed raspberries). It took days for some to get the courage to come to my hand - but they did come to associate me, and my hands, with good things - treats! Once in the run, where they have space to move away or not, I find that when I sit down, they will come up to me. I can reach down and pick up most; others will hop onto my lap. The name of the game is patience, and allowing them to come to you. They will become friendly!