Sensitization, in psychology, refers to a non-associative learning process through which repeated exposure to a stimulus results in the progressive amplification (increasing strength) of the reaction to the stimulus. The organism is becoming more sensitive to the stimulus as time progresses. For instance, a dog normally loves to ride in the car, but after a few trips to the veterinarian the dog makes the association that the car that takes it to see the vet is responsible for hurting him. For this reason, a dog might start to resist riding in the car. Another example could bee seen in a child who is bullied at school. Initially it doesn't bother them that much but as time goes on and the stimulus (bullying) is re-experienced repeatedly then the child may experience a sensitization to social activity and start to fear other schoolmates in general, perhaps becoming antisocial, withdrawn, and very upset about social interactions.