The feelings of attraction may seem magical, but they're actually very real and scientific. Whether or not you are attracted to someone depends on the outcome of your brain running a complex series of calculations.
All five senses play a role in attraction. For instance, the eyes. We may see this as the most logical sense to judge whether you are attracted to someone, but beauty is socially constructed depending on the decade and culture. So, knowing that, why do you still care about the other sex having smooth scar free skin and lustrous hair? Those traits, along with some others, signal youth, good health, and fertility. As un-sexy as it sound, we want someone who looks fit for reproduction (even if you don't want children). When our eyes spot something of interest, we move closer to get a better look. By moving closer, our other senses get a chance to investigate.
Our noses get to judge pheromones, chemical signals our bodies give off that convey genetic information. Pheromones trigger a physiological or behavioral response in the recipient. Women are move attuned to picking up MHC molecules. MHC, or major histocompatibility complex, has to do with the immune system. Women prefer men whose MHC is very different than theirs. This makes sense because their offspring would get a greater variety of immunities.
Our ears judge whether we are attracted to a voice. Men prefer women with high pitch and breathy voices. These traits indicate a smaller body size. Women prefer men with low pitch voices, which indicate a larger body size.
In terms of touch, physical coldness is associated with emotional coldness. Physical warmth is associated with emotional warmth.
The first kiss is also an important factor. The kiss is an exchange of tactile and chemical cues, such as the smell of the person's breath and how they taste.
Chemicals involved in love include testosterone, estrogen, nerve growth factor, norepinephrine, dopamine, serotonin, oxytocin, and vasopressin. Once your body has confirmed that you are attracted to the person, your heart beats faster. Your pupils dilate and your body releases glucose for additional energy. This is your body telling you that something important is happening - so you should pay attention.