Summary by @tldr:

According to the experiment report, not a single spark of MRI activity was flaring from the frontal lobe--the part of the brain where feelings are processed.
Instead, the readings indicated similarities to a disease, an illness--a series of biochemical reactions that trigger an emotional cascade, impairing normal functioning.
Belly aches, overactive sweat glands, nervousness, paranoia, insecurity, obsessions, delusions; the parallels are pretty much identical.
It picked during the era of Romanticism (1800-1850) as a reaction to Renaissance and carried on until recently with the manifestation of the romantic notion of the nuclear family.
image credit The 3 Stooges of Procreation People perceive love quite differently based on their socio-cultural upbringing.
It is much like the perception of a supernatural being, a God for which everyone has developed a private heresy, a buffet of beliefs, according to one's moral convenience.
image credit A Cultural Imperative Love exists because we hold dear of specific attributes about human nature.