Love on the Brain
Scientists peeking inside our brains and psyches have more clues than ever about the biology of love -- why we're attracted, why we fall so hard, and what makes us stay.
The Biology of Love: Smell Counts
Aside from biology and brain activity, body odor is important and help may dictate who we are attracted to and our romantic behavior. "It may be one of the first things that inspires us to say yes or no," says Charles Wysocki, PhD, a researcher at Monell Chemical Senses Center in Philadelphia.
Preference for human body odors is influenced by both gender and sexual orientation, Wysocki and his colleagues found in their research, published in 2005 in Psychological Science. When his study participants of different orientations and genders were asked to choose between distinct odors -- straight men, gay men, straight women, lesbian women -- each picked the odor of a partner of the preferred gender and orientation.
''A person's body odor is determined by a number of factors," Wysocki says," and among them is a set of genes that regulate the immune system." This cluster of genes is called the major histocompatibility complex or MHC. "This MHC confers on an individual an odor print," says Wysocki, citing others' research. And experts have found that a person will seek out a partner with an MHC different than his or her own. "MHC is so variable, no two are alike," Wysocki says.
The Biology of Love: The Script Counts
Once you're initially attracted to someone -- helped along by hormones, odor, or other unconscious factors -- what the other person does or doesn't do counts, too. "You become more attracted to people who are attracted to you," Fisher says.
For instance, one research participant told Aron: "I sort of liked this woman and she came over and sat by me." Things developed.
A woman told Aron she was talking to a friend about her piano instructor and the friend said, "You know he likes you." At that moment, the woman told Aron, she realized she had feelings for him, too.
"When people fall in love, that is the most common scenario," Aron says. "We are looking for the opportunity to love and be loved back."
The Biology of Love: From Butterflies to Comfortable
After people have been in love a while, the activity in the brain reward areas wanes, Fisher has found in further research. "As the relationship matures, it links in new brain areas associated with emotion," she says. "We aren't exactly sure what is going on, but everyone knows romantic love changes over time."