Over the centuries, intelligence has grown with mankind. As mankind has developed new technologies, intelligence too has been altered and developed. Many people who use the word intelligence define it differently then what is usually universally understood to be intelligence, and the both of those groups define intelligence differently from the few who have it.
Some would say intelligence is a means to measure a person's mental acuteness to various factors. The more a person is able to adapt to change, whether they are adaptive to technology and advancement in time or just to the weather, the more a person is seen as intelligent. In this sense, it would make a teenager much more intelligent than many elderly people because youth are much more able to adapt to change then the elderly.
Others would argue that intelligence is how many facts a person can retain in his or her head. For instance Albert Einstein was able to hold many facts in his head so would that make him intelligent? It is generally a fact to say that Einstein was a genius, far more than just intelligent. But to call someone intelligent just because they can recollect a large amount of facts would not be a right thing to do. For example, my uncle can tell you anything you need or want to know about corn, but would that make him intelligent just because he knows facts about corn?
Finally, intelligence could be the accumulative amount of information and education that one can remember. People who have a better understanding of mathematics and social histories are seen as more intelligent as individuals who lack the same understanding. Once again, Albert Einstein had great knowledge in the fields of physics and mathematical calculations; but, his English was fairly