Well, that settles it. When you want to make your employees unhappy just put them in an environment with artificial light only and no windows and take away their greens - plants, that is. According to a study led by Tina Cade from the Texas State University and Andrea Dravigne of the San Marcos Nature Center, the presence of plants in your work environment could have a significant impact on your happiness.

"We pretty much found out that if you had windows and plants or even if you just had plants in your office, you were more satisfied with your job. We thought it was important for offices because a lot of times people are looking for ways to keep employees happy and do all these expensive things like put in a daycare or a workout room. Maybe for less investment they could put in a few plants in strategic places", Cade said.

The study was based on the reports of 450 office employees working in Texas or in the Midwest regions of the United States. People with plants and windows in their offices seem to feel very good about their job, as opposed to people working in offices with no windows or plants. About 82 percent of the people working in places with both plants and windows said they were feeling very happy regarding their work, as compared to only 69 percent of people working in windowless offices and 60 percent of those having only windows and no plants.

Only 58 percent of the people having no windows or plants in their work places have proven to be satisfied with their jobs. 0.8 percent of those working in similar conditions said they felt miserable.

"I was really surprised that having a plant in your office appeared to be more beneficial than having a window in your office. Everybody says, 'I need a window!' but actually it seemed like a plant could be a suitable alternative", said Cade.

The results are statistically insignificant in terms of position, salary, age or ethnicity. Additionally, men seem to be especially affected by the fact that the working environment lacks both windows and plants.

"People will say that women react more to flowers and green stuff, but we actually saw the biggest differences in the guys. Based on what we've found, it needs to be considered in planning. A lot of times these things are seen as luxury items, but this speaks to the importance of trying to keep spaces green, both inside and outside", Cade said.