Being as I'm almost always plastered in floral prints, doodling flowers, and trying to find creative uses for the petals, I started to wonder why this symbol seems to have such an extreme impact on people. Throughout history people have spent countless hours working on cultivating flowers. The perfect shape, color, and smell are just some of the qualities that individuals have dedicated their lives to. However, unlike so much agricultural work, the flowers produce no food and not all posses medicinal qualities.
According to an evolutionary psychology study entitled An Environmental Approach to Positive Emotion: Flowers, there are three possible reasons why flowers act as a mood enhancer for humans, "(1) simple learned associations of flowers with positive social events, (2) associations of flowers with food that could be part of an evolutionary response promoting food search, and (3) flowers as specially evolved human sensory mood enhancers." The concluding hypothesis in this study supports the third reason, "cultivated flowers fit into an emotional niche - their sensory properties elicit human positive emotions. The flowering plants are thereby rewarding to humans and in return, the cultivated flowers receive propagation that only humans can provide."
Studies have shown that flowers elicit a longer-lasting positive mood than other "similar stimuli" (for example: candles, fruit baskets, etc.). People who received flowers also tended to display them in a living room or shared space, and had more consistent positive behavior around their peers.
So if you find yourself moping around on a slushy day, take the time to go out and buy a bouqet. Your mood may just lift enough to bring a little bit of spring into a dark February evening.