(upbeat music)
- [Narrator] You can't stop thinking about them.
You can't eat, you can't sleep,
and you're stumbling over your words.
You're acting a little obsessed.
And you really can't help feeling like you're falling in--
- Love.
That's my name, I mean.
- No. Cool, it's nice to meet you, Love.
No way.
- Yeah.
- [Narrator] So what's going on in your head?
(upbeat music)
These are all the strange things love does to your brain.
What is love exactly?
- It's mostly chemicals.
Dopamine, Oxytocin, Serotonin.
To activate all three;
exercise, eat some protein, squeeze in eight hugs a day.
- That easy, huh?
- [Narrator] Or if you're watching this classic
from Wonder Showzen, it's--
- A neurochemical con job.
- [Narrator] And there might be some truth to that.
(dramatic music)
- [Dr. Fisher] Every time you feel anything,
there's something going on in the brain,
because that's the conductor of the orchestra.
- [Narrator] Dr. Helen Fisher
has spent decades of her life
studying all the weird things love does to our brains.
She's written six books about it.
And she's the first person in the world to use fMRI machines
to study the brain circuitry of romantic love.
She says there are three parts to it:
sex drive, intense romantic love,
and deep feelings of attachment.
- You're going to love me for this.
- [Narrator] In 2005, Dr. Fisher looked at the brains
of 2,500 different college students.
Subjects looked at pictures of their lovers
and pictures of strangers,
and it turned out that two areas of their brains lit up
when they saw their lover:
the caudate nucleus and the ventral tegmental area, or VTA.
The caudate nucleus detects rewards, like love interests.
And the VTA is a little factory near the base of the brain.
It manufactures dopamine and sends it out.
So when the VTA is active, you're feeling good.
And the more you keep seeing your new lover--
- [Dr. Fisher] That brain system will just keep on cooking.
It's a basic brain system, like hunger or thirst.
It just keeps on cooking.
- [Narrator] The VTA is also closely linked to addiction,
which is why new love can actually feel like a drug.
Cocaine, for example,
floods your brain with so much dopamine, you feel euphoric.
Dopamine starts flowing
even when you're just expecting a reward.
Maybe you're anticipating a kiss.
Your brain releases dopamine to prep for the big reward,
and once you do it,
there's even more dopamine released
to reinforce that reward.
You want to do it again, and again, and again.
A study at Stanford University even found that,
just like some addictive substances,
love actually kills pain.
In 2010, researchers posted flyers looking for students
who were less than 9 months into dating someone.
All 15 participants had to bring photos of their new lover
and photos of an equally attractive acquaintance.
Then researchers scanned their brains using an fMRI machine
while flashing the different pictures in front of them.
The catch?
Each participant had a small probe attached to their palm
that was heating up enough to hurt.
But when they were gazing at their lover's photos,
the students reported 12% less intense pain
and 45% less moderate pain.
And the scientists found something else.
Compared to using distraction as a way to kill pain,
romantic love uses a deeper,
more primitive part of the brain.
That could be because experts say,
love is actually a drive we have.
It's even deeper than rational thought or emotions.
- [Dr. Fisher] That is why people pine for love
and live for love and kill for love and die for love.
It's a drive.
- [Narrator] But while your brain is releasing
all that juicy dopamine during the honeymoon phase,
it's also depleting your serotonin.
- [Dr. Fisher] There's now data
that when you're madly in love,
the dopamine system is more and more activated
and the serotonin system is less and less activated.
- [Narrator] Low serotonin causes all kinds of things.
Unstable moods, anxiety, depression,
memory issues and trouble sleeping.
And these low levels found in people deep in love
actually look similar to people who have OCD.
This could be why you feel so obsessive
at the start of a relationship.
And while you're busy obsessing,
you're also likely to miss any red flags.
- But he's obviously not into you.
- Yeah, well that's impossible.
- [Narrator] Because your brain region
linked to negativity bias starts to slow down too,
so you can overrule any bad things about your new lover.
We usually commit negative thoughts to memory
more easily than positive ones.
It's one of our brain's defense mechanisms,
making us remember who our enemies are.
You literally have to let down your defenses
to fall in love.
- I wolf you.
- I wolf you too.
- [Narrator] The good news is, if the relationship lasts,
all of those intense feelings start to level out.
Serotonin goes back to normal,
so you feel less anxious, less obsessive.
- [Dr. Fisher] You can eat and sleep again.
You don't have the butterflies in the stomach.
You're not short of breath.
You're not stuttering around them.
You're not overthinking it to death.
- [Narrator] Of course,
not all relationships make it this far.
And your brain does weird things
when you're rejected in love, too.
- It's over.
(serene music) (door opens, closes)
- [Narrator] Dr. Fisher also scanned the brains of 17 people
who were in different stages of their breakups.
Some as recently as three weeks,
others as far out as 17 months.
- [Dr. Fisher] That was the hardest study I did,
because they're in such pain.
I mean, they're in such distress.
- [Narrator] The study found activity in three brain regions
linked with craving and addiction,
along with the VTA, the little dopamine factory,
still pumping out the neurotransmitters.
Because people were still in love despite being rejected.
She also found activity in the ventral pallidum,
where feelings of attachment come from.
And finally,
she found activity in a region linked with physical pain.
- [Dr. Fisher] This brain region becomes active
when you've been rejected in love.
It also becomes active when you have a violent toothache.
- It's okay.
- [Narrator] So then why do we keep
putting ourselves through it?
Why this evolutionary drive to partner up?
That's where these guys come in.
Prairie voles.
And their cousins, meadow voles.
One of them mates for life and the other doesn't.
- [Dr. Carter] That's oxytocin talking.
- [Narrator] The molecule that makes us feel attached.
To study it, Dr. Sue Carter looked at
why prairie voles formed social bonds the way humans do.
She says it comes down to a system
of oxytocin and vasopressin.
Vasopressin is about arousal.
Think of it as the fire your body sends out
when you're falling in love.
Oxytocin comes in to put out that fire.
But if you've got too much vasopressin
and too little oxytocin, it keeps burning up.
- [Dr. Carter] It literally could destroy the tissue.
- [Narrator] You can't keep that intense feeling
of falling love forever, as much as you might want to.
In humans, oxytocin is released during sex,
childbirth and breastfeeding,
but also when you do things like spend time with friends
or pet your dog.
It's all about bonding
and it acts as an anti-inflammatory in our bodies.
Dr. Carter thinks this is why secure relationships
actually help us live longer, healthier lives.
And that's why it can feel so involuntary
to form attachments to people.
Even if the rational part of your brain
might be telling you not to.
- [Dr. Carter] I think loving relationships,
secure relationships, are so important to human evolution
that they were not left to cognition.
They embedded in the oldest parts of the brain,
the brainstem, the areas that regulate our whole body.
So we can't just think away our feelings.
- [Narrator] But the science here can only tell us so much.
It's hard to study love
because there are so many kinds of it.
People all experience it in their own unique way.
And most money for research goes to curing disease,
not figuring out why we fall in love.
There's also more to understand
about why some couples stay in love for decades
and why some don't.
In 2011, Dr. Fisher studied couples
who had been together for decades,
and the same areas of their brains lit up
as people who had just fallen in love.
- [Dr. Fisher] So, you can remain in love,
not just loving, but in love long-term.
It just requires choosing the right person.
- [Narrator] Ultimately,
love isn't something we can live without.
- [Dr. Fisher] Nobody gets out of love alive.
We're built to love.
This brain system evolved millions of years ago.
It will survive as long as we survive as a species.
Everybody loves.
We all love in the same way.
Who we choose is gonna be different.
When we fall in love, where we fall in love,
how we express our love
will be different from one person to another,
from one culture to another.
But the fact that we love is human.
- [Narrator] So, you may as well go for it.
- None of us know anything. You know?
But you put on your big girl pants
and we give things a shot.
(playful music)
- [Narrator] Is love at first sight real?
According to a Dutch study in 2017,
you probably just thought they looked really good.
Out of 396 participants,
only 32 people reported feeling love at first sight.
The majority were men,
and it was pretty rare the feeling was mutual.
Mostly,
it was linked to how attractive people found each other.
But, hey, there's always a chance.
(playful music)