Have you heard of the Flynn Effect?

In the 1980s a political scientist named James Flynn (University of Otago, New Zealand) found that over the last century, in every nation in the developing world where intelligence-test results are on record, IQ test scores had significantly risen from one generation to the next.

IQ tests may not be a great way to test intelligence, therefore we may not be smarter than previous generations, but our brains are different. Here is a article where Flynn discusses those points if you are interested.