Capgras Delusion is when someone thinks that a person they know, like their mother or father, has been replaced with an imposter. They might look exactly the same, but the person with Capgras Delusion thinks they are not the same person. It's like when you play dress-up and pretend to be a superhero, but instead of pretending, the person with Capgras Delusion really thinks someone else is wearing their loved ones' skin like a suit. This can be very scary and confusing for the person with this condition. Scientists don't know exactly why some people have Capgras Delusion, but they think it might have something to do with the way the brain processes information about faces and emotions.