Geniophobia (from Greek genio, meaning "chin" or "jaw") is the fear of chins. People can have this fear because some people have prominent chins, like having double chins. Most people with this phobia feel obsessed with other people's chins, especially those with imperfect chins. Some may fear chins because they might have fallen down in the past and injured their chins but this is very unlikely because the chin is one of the least injured parts of the face. Geniophobes can't stop looking at other people's chins and may even avoid interacting with people whose chins they consider as hideous or deformed. They may become introverts in extreme cases.
Treatment includes behavioral and cognitive therapy. Since all of us have chins, for those with severe geniophobia, medications may be needed to alleviate symptoms.