Positive emotions generally work in an opposite way to negative emotions. So, while emotions like fear, anxiety, stress and anger narrow our focus, inhibit our concentration and decrease our cognitive abilities, positive emotions can do the opposite.
When we’re feeling upbeat and happy, we’re more likely to have an inclusive focus than a self-centered outlook, and to perform better on cognitively demanding tasks.
This is one of the main reasons that positive encouragement works better than criticism. Read more at http://buff.ly/1dMgKOS