Who is the Smartest Person on Earth

There are many contenders such as Einstein and Hitler.

Out of all the extraordinary minds that have graced this planet, who is the most intelligent? There are many candidates for the accolade: Einstein, Newton and Marie Currie.

Does the answer to the question have a darker answer? Could it be Hitler, Stalin or Vlad the Impaler? 

The answer lies in how we measure intelligence. What are the markers for a genius? If it true scientific knowledge? You would suggest Einstein or Newton.

If it is measured on the ability to communicate, control others and strategies problems. In this case, we could put Hitler as a contender. Generally speaking, the IQ test is seen as a good reference of who the smartest person in the world is.