Joan was bitten by a chihuahua when she was five years old. as a result she is now afraid of all dogs, no matter the breed. this is an example of:

This is an example of "S timulus Generalization".

Stimulus generalization, in the conditioning process, is the propensity for the conditioned stimulus to summon likewise reactions after the reaction has been conditioned. For instance, if a youngster has been conditioned to fear a stuffed white rabbit, it will show signs of fear of articles like the conditioned stimulus, for example, a white toy mouse.