Biological basis

Biological models of sex hunger or thirst as much love as a mammalian drive, go to see. [18] Helen Fisher, a leading expert in the topic of love, partly overlapping the experience of love is divided into three stages: lust, attraction, and attachment. Sexual desire is a feeling of lust, romantic attraction determines what partners mates find attractive and pursue, by choosing to conserve time and energy, and a home, parental duties, mutual defense, and human feelings of safety and security involving shared attachment included [. 19] Three neurotransmitters, including behavioral patterns and three distinct neural circuitries, are associated with these three romantic styles. [19]

Lust is the initial passionate sexual desire that promotes mating, and increased release of chemicals such as testosterone and estrogen is involved. These effects rarely last more than a few weeks or months. Sexual attraction for more individualized and romantic desire for a specific candidate, which is a person's friend out of lust as commitment to forms develops. Recent studies in neuroscience have indicated that as people fall in love, the brain consistently a certain set of chemicals, including pheromones, dopamine, norepinephrine, and serotonin, which act in a similar way for amphetamines, brain stimulating the pleasure center and leading to releases heart rate, loss of appetite and sleep, and side effects such as an intense feeling of excitement. Research has indicated that this stage generally lasts one and a half to three years. [20]
Since the lust and attraction stages are both considered temporary, a third stage is needed to account for long-term relationships. Attachment relationship for many years and decades promotes lasting relationships. Attachment usually married and commitments such as children, or on mutual friendship based on things like shared interests. The short-term relationships chemicals oxytocin and vasopressin to a greater degree than has been linked to high levels. [20] Enzo Emanuele and coworkers reported the protein molecule nerve growth factor (NGF) is known as the high levels when people first fall in love, but these return to previous levels after one year. [21]