Even though people don't realize it, when someone sees or smells another person, it sparks a neurochemical reaction.
According to Scott Wersinger, assistant professor of psychology, hormone levels change in response to sensory cues. If specific areas of the brain are stimulated, it results in sexual attraction.
The main hormone involved in social interaction is oxytocin, according to Wersinger. When oxytocin is released, people get a rewarding feeling from social stimuli.
In order for two people to be sexually attracted to each other, the hypothalamus gland must be active.
"Anything you can think of that's fun is mediated by the hypothalamus," Wersinger said.
However, the hypothalamus isn't the only thing that makes people fall head over heels for each other.
"People can be attracted to each other without love," Wersinger said. "They're not the same."
According to Wersinger, attraction in humans is not as simple as stimuli and chemical reactions. The process gets complicated when the brain's cortex is involved. The cortex is where higher brain functions such as sensory coordination, learning and memory occur.
"Attraction is a lot more than just our gut reaction," Wersinger said. "We think about it... we don't act on impulses."
For attraction to occur, the cortex has to be on board with hormonal desires.
"The cortex overrules everything," Wersinger said. For example, if the brain receives a signal that you're hungry, it doesn't necessarily mean you'll eat, he said.
Another area of the brain important to romance is the amygdala, which is the center of emotion. According to Wersinger, studies conducted to evaluate the difference between sexes when it comes to attraction have proven that men have a more active amygdala and hypothalamus than women, even though each gender was equally aroused by a visual image during experiments.
"This shows that the neuro-basis for attraction and love is going to be different between men and women," Wersinger said.
Research in this field is "not very scientific," Wersinger said. Typical experiments with humans use visual or scented stimuli, such as a sexual image or the unwashed t-shirt of the participant's partner, to evoke a reaction. The reaction is measured by neuroimaging technology.
Psychologists and scientists don't know exactly what to make of these differences yet, he said.
"It's important to understand as much as we can about why we behave the way we do," Wersinger said. "There are times when attraction and friendship can go really wrong and in order to fix that, we need to know how it's supposed to work."
According to Wersinger, the studies mostly help researchers develop cures for aspects of disorders like autism and schizophrenia, which involve social withdrawal.
Therefore, love remains a mystery to even the scientific community, and Wersinger thinks it might have to stay that way.
"With something like love, I don't like breaking it down into chemicals, neurons and brain areas. I think love is something specific to humans and we should just enjoy it rather than try to figure out how to control it," Wersinger said. "Thinking about a bunch of chemicals takes the romance out of it."
However, Wersinger also said that there are studies showing chocolate as a possible stimulant neurochemical involved in attraction.
"I'd get fired for saying any of my other tips," Wersinger said.
Nobody ever said attraction was easy.
