Valentine's Day: Love is a state of mind

You see that person across the room and feel urgently compelled to talk to them. Love at first sight?  More likely dopamine and serotonin flooding your brain. 

Or you’ve hit it off and are cohabitating or engaged within months. Fate? More likely a flood of oxytocin.

The heart gets all the attention on Valentine’s Day, but it’s really a series of reactions in the brain that drive us to pursue meaningful relationships with the ones we love.

“Love is the result of chemical changes that happen in the brain when we meet someone and feel that connection,” UW Medicine neuroscientist Larry Zweifel said. “There are long-term changes in our brain when we connect with someone that link us to those individuals, sometimes for life. I think that's tremendously fascinating.”

[Download broadcast- and web-ready video with Larry Zweifel.]

Those chemical changes — or their absence — might also explain why many people feel melancholy on Valentine’s Day when they aren't in a loving relationship.

“People can be filled with a sense of dread as that date approaches, and there are many reasons why someone might feel averse to the thought,” Zweifel said. “Holidays that come with high expectations can be a major source of stress.”

The professor of psychiatry and behavioral sciences said chemical reactions can explain behaviors ranging from the impulse to love to the impulse to fight.  Scientists know how our brain and body react to many chemicals, but they are also discovering new chemical drivers of behavior. 

In terms of establishing desire, chemically speaking, first impressions are crucial, Zweifel said.  “It's how the brain processes those initial responses and that social feedback that determine whether or not we'll engage with another individual again in the future, or whether we will do our best to avoid them."

If our brain likes what we see, the first reactions are increases in dopamine and serotonin, key neurotransmitters that drive sensations of pleasure and reward. Such a chemical rush can cause an introverted person to approach a stranger to say hello.

“It's that surge of dopamine and serotonin, as well as numerous other peptides and hormones ... that push us to engage with that person,” he said.

And if things go well, more chemicals are produced.

“It’s reinforcing,” Zweifel said. “Your brain is like, ‘OK, I can approach this person and they're receptive, so in the future, if I see this person again, I know that I can approach them and talk to them.’ ”

Add in social cues, physical touch and other inputs, and the brain’s response is to bring the neuropeptide hormone oxytocin into the mix. It’s also a neurotransmitter that induces brain changes that help us form bonds. It’s what leaves us with a sense of overwhelming contentment.

Scientists have seen the effect of a flood of oxytocin on the brain in the aptly named prairie vole, which, when partnered, form monogamous bonds afterward.

“In humans, we think it's a very similar action where when we meet someone and we find a connection. There's an increase in oxytocin, which rewires our brain so that now we have an emotional attachment to that individual,” Zweifel said.

Our brains don’t always make it to the oxytocin stage, for one reason or another. Perhaps the nonverbal cues we need to move forward aren’t there. Or our brain doesn't generate enough of the chemical to support a durable change.

“Love at first sight may seem like love but it’s really just the initial surge of neurotransmitters and hormones that were driving it. It takes time to form that real connection,” Zweifel said.

The bonds formed by oxytocin can break down over time, too. Work, family, money and infidelity are all stressors that can rewire the brain.

“Stress is something that can really put the brakes on our positive emotions,” he said.

Even silly things like heart-themed holidays can cause stress. While new couples might depend on Valentine's Day to up the ante, Feb. 14 might be poor timing for a relationship reboot.

“It’s also a significant stressor, and stress can actually have a powerful influence over those warm, fuzzy feelings that we have,” Zweifel said. “If something causes a stress, it's going to reduce those reinforcing and rewarding signals that are motivating us to socially interact with the people that we care about. It can actually have the opposite effect.”

Written by Chris Talbott - 206-543-7129, talbottc@uw.edu 

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