There are a lot of types of smile.The one who smiles from the bottom of his heart is experiencing the most wonderful feeling throughout the entire cosmos,but rather,we call it laugh,instead of just "smile".Therefore,when we say a person is smiling,there are some underlying aims or we regard that he smile on purpuse,no matter good or bad his purpose is,he is not natually happy.However,smile on purpuse could make a man happier by doing this action because when he is really yearning for happyness and act as a cheerful person,happyness is after him.you are good in English.but there are some small mistakes in your article.happyness is not the right spelling,right?