IQ tests measure a person's mental age and abilities against their chronological age - if you are 20 years old and are thinking at the test's definition of an average 20 year old your score will be 100, if you've developed more slowly the number will be lower and if you're thinking at a more advanced rate than normal the number will be higher. Humans don't all develop at the same pace: in highschool I was considered a trouble student with a learning disability, and when I went to university I was one of the most successful and active students in my seminars

Our IQ is not completely static and may change as we age. For raising IQ scores: we can learn to develop habits and patterns of thought in order to make the most of the information we're receiving, we can learn to question more frequently and to try to understand the situations we find ourselves in more carefully, and we can keep reading and engaging creative activities in order to stay as mentally able as possible. Diet and medication can sometimes also have an effect on our ability to process information and would effect any IQ test you may take (Humans don't think as well when suffering from a sodium deficiency, as an example)