From the fourth paragraph the passage believe that there are unhappy times of life-typically the stress –filled teen years, the “ mid-life-crisis” years, or the declining years of old age, and at the end of they said the age is not infecting the happiness of people. I found an interest word of depression .how did the depression come out? We can learn it from press; de—press—ion .the meaning of press that if you press on, you continue working. The forced of you need to work for some people. You will feel not very well, how describe this experience? So I think human invent depression, add the de the head of press. This is a verb, and then makes change, at last produce the depression.
Also the fifth paragraph about the scientifically research of sex for infecting of happiness. At last the conclusion is grounded in scores of studies around the world. I don’t know the real meaning of grounded in here.
