Since ever, people have been searching for true love.

What's that "something" that your partner has and other potential mates do not?

A research made by Mark B. Kristal, professor of psychology in the University at Buffalo College of Arts and Sciences, found that that particular "something" consists in several physical elements and is triggered by the proper time, order and place. "There are several types of chemistry required in romantic relationships," said Kristal. "It seems like a variety of different neurochemical processes and external stimuli have to click in the right complex and the right sequence for someone to fall in love."

The smell is essential in accepting a partner, and is a learned issue or biased by cultural preferences (for example Europeans employ softer perfumes than Africans do). "Smell forms part of the framework that conforms to cultural attractiveness standards; for example, smelling like a strawberry instead of mildew," he says.

Human pheromones must have something to say in the sexual chemistry. "Pheromones are unlearned, and perhaps unsmellable, signals that enter the brain through the olfactory system. They can function in sex, alarm, territoriality, aggression, and fear," said Kristal. "While sex attractant pheromones may explain changes in libido, they don't explain why we choose a specific person for a mate."

"In humans, specific mates are more probably chosen on the basis of other sensory cues: visual, regular olfactory, auditory and tactile cues," Kristal notes.

Smell can turn out to be a very important piece of the puzzle. "After a certain amount of bonding, specific mates may be more recognizable to each other by smells rather than by pheromones. Studies show that people can recognize unwashed t-shirts belonging to their mates by the smell."

Love feelings are also associated with increased amounts of some brain chemicals. "Two related brain peptides, vasopressin and oxytocin, have been shown to be involved in both the permanent or long-term social bonding that underlies mating," added Kristal. "The neurotransmitter dopamine, in a part of the brain called the VTA, is certainly involved in the rewarding properties of love and sex."

All kinds of aphrodisiacs, from foods, drugs to rhino horns and tiger penis bone, believed to rise the libido are just crap: when you are not attracted enough by somebody, that's it, nothing's gonna change it.

Kristal believes that you'd better "smell good and look successful" in order to attract a potential mate.