Teenagers The teenager is a creature far different from that of any other. These strange beings are classified into the species of the homo sapiens ranging from thirteen to eighteen years of age. Through the years, it seems that a teenager has grown more to be a separate class in itself rather than a certain time period in life. Although teenagers are really almost a separate sub- species of the human race, none of them are really quite the same. The teenager may be divided into three separate categories ranging from the radical, moderate, and conservative. The "radical" teenager may be best described as one going to all extremes