This is not a silly question. There is ample evidence in my family that four-year-old's are smarter today than any four-year-old I knew a generation ago.
It is a fallacy to think that there may be some genetic or evolutionary change. There isn't.
It is also possible that the evidence of data is against me. School test results don't seem to be higher. On the other hand the population that takes these tests has been growing steadily.
I think that the perceived level of intelligence in the populations I deal with has been increasing.
I give commerce 100% credit.
Let's do a thought experiment. Let's assume you were living in an agrarian society where 90% of the jobs were agricultural. What level of talent and skill would you encourage in your children?
Now look at our contemporary commercial society and think about the nearly infinite number of market functions that will support a middle-class lifestyle. A child being raised in our current environment can be encouraged to develop every imaginable talent and skill because that child will likely be able to use that extraordinary human element of diversity in our commercial world.
It is the application of that extraordinary human diversity that I believe I am perceiving as an increase in the level of intelligence. Because intelligence is a combination of spontaneity, information database and unique vision people are more likely to have the appearance of more intelligence as they are more able to accommodate the modern world of commerce.
Commerce allows us to become more intelligent humans.