Both positive and negative emotions can drive or hinder productivity, though their specific effect may depend on the individual. In general, negative emotions exert a much greater effect on someone's output. Feeling stressed and anxious about an upcoming deadline, for instance, could motivate one person to work diligently to turn it in early; another person may attempt to avoid such negative feelings by putting the project off until the last second.
Positive emotions such as happiness have also been shown to influence productivity; one study, for instance, found that participating in a happiness-boosting intervention increased productivity by approximately 12 percent. However, happiness's effects on productivity are complex. Other data indicates that while workplace happiness has shown marked decreases over the past decade, worker productivity has gone up, suggesting that happiness and productivity do not always go hand in hand.
For more on the relationship between emotions and productivity, see Mental Health and Productivity.