Human Affection Altered Evolution of Flowers

Human Affection Altered Evolution of Flowers

Flowers make people happy. And while that might seem obvious, there hasn't been much research to prove the point until now.

A trio of new studies by Rutgers University scientists supports the notion pretty strongly, and the experts go on to speculate that flowers have flourished on this planet, with their beauty evolving in recent millennia, partly because humans are so attached to them.

The first study involved 147 women. All those who got flowers smiled. Make a note: all of them. That's the kind of statistical significance scientists love. Among the women who got candles, 23 percent didn't smile. And 10 percent of those who got fruit didn't smile.

Okay, that's just one study. Let's try another.

In an elevator, 122 men and women were given either a flower, a pen, or nothing. Those who got flowers smiled more, talked more, and -- here it gets interesting -- stood closer together.

Finally, in another test, bouquets were delivered by florists to 113 men and women in a retirement community. All 113 got flowers and a notebook, but some got them earlier and received a second bouquet when the others got theirs. By now you can guess the outcome. The more flowers, the more smiles.

From there, it's a bit of a leap to the idea that flowers are prolific because we love them.

But the results got the scientists to thinking about how the flower industry of today has evolved into growing things that serve no other purpose than emotional satisfaction. Nature won't even pollinate many of the domesticated flowers. Just among roses, there are so many types conjured by humans that, clearly, flowers aren't what they used to be. But it's likely our collective hand has played a role longer than you might think.

Rutgers geneticist Terry McGuire suggests that nature's prettier flowers got to survive and thrive because people didn't destroy them when they cleared land for agriculture. Instead, they cultivated them and have been doing so for more than 5,000 years.

"Our hypothesis is that flowers are exploiting an emotional niche. They make us happy," McGuire says. "Because they are a source of pleasure - a positive emotion inducer - we take care of them. In that sense they're like dogs. They are the pets of the plant world."

Here's one way it might have worked:

Many species of flowers that are now cultivated used to sprout only when the ground was disturbed, McGuire explains.

"As humans moved into agricultural settings these flowers would have been weeds," he told LiveScience. "These flowers might have been tolerated because of their beauty. The seeds would have been preserved -- perhaps initially because they were mixed with crop seeds -- and replanted. Humans would have become the seed dispersers. Over time, the best of these flowers might have been selected and the seeds more carefully preserved."

The idea is detailed in the journal Evolutionary Psychology.

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Robert Roy Britt

Robert is an independent health and science journalist and writer based in Phoenix, Arizona. He is a former editor-in-chief of Live Science with over 20 years of experience as a reporter and editor. He has worked on websites such as and Tom's Guide, and is a contributor on Medium, covering how we age and how to optimize the mind and body through time. He has a journalism degree from Humboldt State University in California.