Think of the last time you ran into someone you find attractive. You may have stammered, you may have said something incredibly silly or foolish and tripped spectacularly. And chances are, your heart was thudding in your chest.

It’s no surprise that, for centuries, people thought l...

The testes and ovaries secrete the sex hormones testosterone and estrogen, driving sexual desire.

Dopamine, oxytocin, and vasopressin are all made in the hypothalamus, a region of the brain that controls many vital functions as well as emotion.

Lust and attraction shut off...

The story is somewhat similar for oxytocin: too much of a good thing can be bad. Recent studies on party drugs such as MDMA and GHB shows that oxytocin may be the hormone behind the feel-good, sociable effects these chemicals produce.

These positive feelings are taken to an extreme ...

And finally, what would love be without embarrassment? Sexual arousal (but not necessarily attachment) appears to turn off regions in our brain that regulate critical thinking, self-awareness, and rational behavior, including parts of the prefrontal cortex.

in short, love makes us d...

Last but not least, attachment is the predominant factor in long-term relationships.

While lust and attraction are pretty much exclusive to romantic entanglements, attachment mediates friendships, parent-infant bonding, social cordiality, and many other intimacies as well. The two prim...

Lust is driven by the desire for sexual gratification. The evolutionary basis for this stems from our need to reproduce.

The hypothalamus of the brain plays a big role in stimulating the production of the sex hormones testosterone and estrogen. While these chemicals are...

This all paints quite the rosy picture of love: hormones are released, making us feel good, rewarded, and close to our romantic partners. Love is often accompanied by jealousy, erratic behavior, and irrationality, along with a host of other less-than-positive emotions and moods. It se...

Oxytocin is often nicknamed “cuddle hormone” for this reason. Like dopamine, oxytocin is produced by the hypothalamus and released in large quantities during sex, breastfeeding, and childbirth.

The common factor here is that all of these events are precursors to bo...

According to a team of scientists led by Dr. Helen Fisher, romantic love can be broken down into three categories:

• lust - driven by testosterone and estrogen
• attraction - created by dopamine, norepinephrine and serotonin
• attachm...

These chemicals make us giddy, energetic, and euphoric, even leading to decreased appetite and insomnia. In fact, norepinephrine, also known as noradrenalin, which play a large role in the fight or flight response, kicks into high gear when we’re stressed and keeps us alert.

Brain ...

The dopamine pathway is particularly well studied when it comes to addiction. The same regions that light up when we’re feeling attraction light up when drug addicts take cocaine and when we binge eat sweets.

Cocaine maintains dopamine signaling for much longer than usual, leading ...

That is, as we become more attached to our families, friends, and significant others, oxytocin is working in the background, reminding us why we like these people and increasing our affection for them.

While this may be a good things for monogamy, such associations are not always positive....

As we’ve realized by now, it’s not just the hormone side of the equation that’s complicated. Love can be both the best and worst thing for you – it can be the thing that gets us up in the morning, or what makes us never want to wake up again. I’m not sure I could...

What is love?

Scientists in fields ranging from anthropology to neuroscience have been asking this question for decades.

The scientific basis of love is often sensationalized, and as with most science, we don’t know enough to draw firm conclusions about every piece of the puz...