Phobia acquisition can be learned through association. What is required to produce a phobia is an UCS that produces a strong emotional reaction (fear), and a situation where that UCS can become associated with a NS. This means that there are individual differences in the way the environment influences learning due to the experiences individuals have. For example, if a child is scared when watching a film in the cinema, they may associate the film with the dark environment of the cinema and then feel fear the next time they go to bed as their room is dark.