Joost is planning to buy a hybrid car. When he tells his friends over lunch, they make fun of him, calling him a "crunchy vegan tree-hugger" and saying it's just like him to buy an environmentally friendly car. They never tell him they're just kidding and they actually drive hybrids. Based on his friends' reaction, though, Joost buys a standard gas-powered car. What concept from Social Judgment Theory has Joost demonstrated?