Researchers find it really difficult to identify how emotions developed throughout evolution. It was initially theorized that emotions were learned throughout development, and they were not innate feelings. This means that once stimuli connected an experience with a feeling, they were paired together and created an emotion towards a specific situation. To test these theories, a 9-month old patient in a study was tasked with playing with different objects. These objects included fluffy animals, masks, dolls and more. The patient played with these animals and expressed no distinct or obvious emotion towards any specific object. This disconnect was called the neutral stimuli; the patient did not connect any object to a specific feeling. For the second round, the baby was exposed to a loud noise. As predicted, the loud noise startled the patient and they began to cry. This stimulus is unconditioned because the patient was not exposed to it before, but still was frightened by it. To tie the two together, now the patient was exposed to the same objects accompanied by a loud noise. When the baby reached out for one the objects that initially didn’t scare him, a loud noise would go off, and the baby would be frightened. This taught the baby to associate the loud scary noise with the harmless animal. This indicates how humans can learn emotion through association.