Everyone knows the basics of keeping employees motivated: recognize their achievements, reward their hard work, foster a positive culture, and so on. But these fundamentals only scratch the surface when it comes to understanding how to cultivate a happy work environment.

There are many factors at play when it comes to employee morale, and some influencers are subconscious, murky or much more pervasive than we think. Many entrepreneurs, executives and employees themselves do not fully understand what influences their own emotions and desires throughout the day. Here are some rather surprising, scientific and statistically based facts that may change the way you think about about worker happiness.

1. Stress is the nation’s most underestimated business expense—it costs American businesses $300 billion every single year.

To put that number in perspective, it’s over seven times more expensive than the cost of bad customer service. According to the American Psychological Association, this heavy loss is due to stress-related absenteeism, drops in productivity levels and employee turnover, which chip away at growth throughout the year.

2. Be careful with the AC—being cold can intensify feelings of isolation.

Studies show that being physically cold can lead to increased feelings of loneliness, without the individual being aware of this connection. Meanwhile, a burst of physical warmth—similar to personal warmth—has the power to help people ameliorate feelings of rejection. That being said, consistently high temperatures can also make workers feel sluggish. Experts suggest keeping your office temperature dial around 65-70 degrees Fahrenheit.

3. Hourly employees are happier than salaried ones.

This fact may come as a surprise, but it has been supported by a study from the Personality and Social Psychology Bulletin. Findings reveal that hourly workers feel happier than salaried employees, and researchers theorized this discrepancy might be due to hourly workers’ focus on the concrete “worth” of their time each paycheck.

4. A noisy workplace can unintentionally trigger erroneous releases of adrenaline.

Even though some people claim to enjoy a workplace that’s abuzz with activity, a study reveals that loud workplaces raise levels of epinephrine (also known as adrenaline), whether or not employees report feeling bothered by the noise. Prolonged exposure can lead to unintentional reductions in motivation, trouble sleeping and even poor posture!

5. The No. 1 reason employees leave isn’t money or opportunity.

While circumstances will always vary, many leaders misunderstand the motivations behind employee attrition. Although many workers decide to leave their jobs for a promotional opportunity or a higher salary, a study of more than 10,000 employees revealed that their primary reason for leaving was actually to escape work-related stress.

6. Optimal levels of employee motivation are achieved when they are challenged—but within reason.

Everyone knows that workers prefer to work in a goal-oriented and challenging environment. Studies reveal that in order to achieve the highest levels of motivation and satisfaction, an individual’s task must be difficult yet achievable, and be both perceived as a challenge and objectively be a challenge (based on their skill level). The ability to properly assign and delegate these perfect challenges, of course, falls on a great leader.

7. Flexible schedules unequivocally boost satisfaction and performance while reducing turnover.

Everyone appreciates having a flexible schedule, but it goes beyond simply making employees happy. Employees whose work schedules conflict with their family priorities are three times as likely to quit their jobs, and there are countless examples of successful companies (big and small) that noticed significant reductions in costs when they offered schedule flexibility.

8. Breaking up the day with any sort of physical activity can improve your productivity (even more than it improves your mood).

We all know working out is good for us, but studies show that breaking up the day with any sort of physical activity, no matter the intensity or duration, can improve performance when it comes to increasing output, managing time-sensitive demands and generally being more tolerant of co-workers and yourself. While most of us refer to exercise as a “mood booster” the study surprisingly concludes that productivity is even more positively affected by midday exercise than mood.

9. Employee commuting is directly linked to worse health and steep business expenses.

We all know commuting is a bad thing, but most employers are unaware of how directly it affects their business. The American Journal of Preventative Medicine found that the further people commute, the higher their body mass index and blood pressure, which can adversely affect healthcare costs. Employees who commute get sick more often, and unbeknownst to many, about 5 million workers call in sick every year simply because they can’t handle the stress of their commute. While commuting is usually unavoidable, consider offsetting some of the stress by allowing commuters more flexible work schedules (see No. 6) so that they can work around the traffic.

10. Office layout matters—greater employee proximity and fewer barriers increase job satisfaction.

While everyone needs a semblance of private space to get work done, studies find that being within close walking distance to other employees and having fewer physical barriers (which act as deterrents for conversation) is critical for increasing impromptu and face-to-face employee interaction. These exchanges are essential for employee job satisfaction, collaboration, commitment to a business, communication and overall productivity.

The reality is that happiness is a fickle, finite, precious and elusive resource that will naturally ebb and flow throughout a worker’s career. You will never be able to make every single employee happy all the time, but by understanding the complexity of their motivations (even the ones they might not even fully understand themselves), you may be able to collectively increase the happiness of your team and the success of your business overall.

Article by Rochelle Bailis