Why should ear, nose, tongue and eyes be called special senses? The basic reason is that these are the channels through which we maintain contact with the surroundings. Though apparently it may feel like these are individual sensory organs, they do show some connections. Interestingly, our hearing is less sharp after we eat a heavy food. Isn't it good for a sound nap after a stomach-full meal? That does not mean we go deaf after a heavy meal, but the hearing pitch does change after that. We usually owe it to our tongue that we have taste, but do you know that unless saliva dissolves something, our tongue cannot recognize the taste of the food eaten. Taste is nothing but the food chemicals dissolved in the saliva being sensed by the taste buds present on the tongue. Try to dry off your tongue and mouth with a tissue paper and then taste something. Woman are much better smellers than man. They are born with this characteristic ability and can correctly make out the exact fragrance of the sample. We all can store almost 50,000 different scents, which are strongly tied to the memories. Pupils  do not respond to light alone, but to the slightest bit of noise around too. Thus surgeons, watchmakers and those professionals who have to perform a very delicate job do prefer to have a sound-free environment. Even a small noise can enlarge their pupils, change the focus and make them see less clearly. Each and every one of us has an individualistic or characteristic smell, which is unique to us, except for the identical twins. This smell isn't very noticeable yet can be sensed even by a newborn. It may be due to this scent that the newborn recognizes the presence of his parents around. Many of us can point out the smell of our significant friends and colleagues. This is guided, to a great degree, by genetics but it is also influenced by the environment, diet and so on. This all together creates the unique chemistry that is individualistic for each person. What makes each person different from anyone else except for twins according to the passage?
The particular smell of a person. The characteristics of a person. The style of one's behavior. The ability to distinguish various scents.