"Part of your nervous system is saying 'this is very important to me,'" says Dr. Brown, so the nervousness (the culprit behind those telltale sweaty palms) is natural. Some psychologists actually regard love as an addiction instead of an emotion because it causes these aforementioned behaviors and because it is a "goal-oriented motivational state" like addiction. Love also activates the subcortical and cortical areas of the brain, which are associated with drug cravings. The Chemistry of Love
3. You Can't Keep Your Hands Off Each Other
You won't just be seeking your beau visually. Just as you hunt down food when hungry, you'll actively engage in proximity-seeking behavior when you're in love. This explains why grade-school flirtation often involves pushing or hair-pulling. When in love, we can't resist the urge touch our beloved (luckily, we learn how to do this in more polite and pleasing manners later in life).
Dr. Bianca Acevedo, Visiting Scientist at the State University of New York at Stony Brook, says when we're in love, our bodies will subconsciously lean toward each other, a physical manifestation of the brain's desire for emotional closeness. Have you caught yourself wiggling closer to your lover?
4. You Can't Stop Thinking About Him...
With the increased dopamine levels of romantic love, people think about their romantic interests, on average, 85 percent of the day. This is known as "intrusive thinking."
According to Dr. Brown, "In the early stages of romantic love, most people can't stop thinking about their beloved. The other person becomes an obsession," and will occupy their thoughts for what may seem like an extreme amount of time. But it's really quite normal. In fact, Brown says "If it is less than 40 percent, then it is not really intense romantic love." The level of obsession, while normal if in love, is often compared to that of obsessive-compulsive disorder. When patients undergo treatment for OCD, they're provided with serotonin reuptake inhibitors to ease their obsessions. Because of this, scientists figure that the decrease in the brain's normal serotonin levels causes similar behaviors when in love.
4. ...And Only Him
According to Dr. Brown, when we seek a mate with romantic love in mind, we'd prefer the relationship to be long-lasting. This means we have strong feelings of romantic love for just one person. Conversely, feelings of lust are less about a specific person than they are for sex itself. When it comes to lust, the preferred relationship could be significantly shorter.
According to a 2002 study in which Brown participated ("Defining the Brain Systems of Lust, Romantic Attraction, and Attachment," published in Archives of Sexual Behavior), if a person is really "in love" with his or her partner, desire for emotional union will take precedence over desire for sex. The study also concluded that we seek sexual exclusivity with this one person because we innately hope for uninterrupted courtship and reproduction.
"Love is a survival system, like being hungry or being thirsty," Dr. Brown says. Our bodies seek love (with the goal of reproducing) just as they seek out food or water. Therefore, love for one person is more like a reflex. Love: 15 Signs You're Meant To Be
[Writer's Note: While people won't die without love, as they would without food or water, Dr. Brown says studies have shown that people in relationships live longer; they also tend to be healthier and have a greater sense of well-being. The love of friends and family is also important and can even occasionally substitute for romantic love. However, the kind of love we seek depends very much on our hormonal status, what our bodies need at a certain moment in time.]
But Remember, It Doesn't Last Forever
Unfortunately (or fortunately, depending on how you look at it), the heightened emotions and general euphoria brought on by romantic love eventually fade.
"You can't keep it up forever or you'll never get anything done!" laughs Dr. Brown. "It's too intense to last. Even the most intense [romantic love] doesn't last more than six months." But don't worry. As feelings of intense romantic love wane, feelings of attachment develop and that's what keeps people together for the long run.
"You can have just 'attachment' but it's better for the [couple] if there's romantic love [at the start]. People stay together because they remember the warm, positive feelings of having that original, romantic love." This way, a couple won't just "stay together for the kids"; they will stay together for each other. That attachment is then transferred to their offspring. So love itself doesn't necessarily diminish. It just evolves.
Despite all the signs and science, though, if you're in love, you're in love. Even Dr. Brown agrees: "You know when it happens."