Interesting question. I guess the first thing we need to decide upon is what is the definition of “stupid”? According to Merriam-Webster, stupid is “not intelligent : having or showing a lack of ability to learn and understand things”.
I’m going to go with the not intelligent aspect. Since it’s intelligence, there’s a fairly well-known and common measurement tool available called the Intelligence Quotient or IQ. For some background information, the IQ test is made up of several different standardized tests. These tests may be visual, verbal, physical or a combination of several types. Without getting into too much of the math behind it all, a person’s IQ score falls on a scale where the average score is 100. So given a large group of people, say the entire human population of Earth, if everyone was tested, the average would be 100. Why? Because that’s how the scale is defined, just accept the fact that half of the people in the world are less than or equal to 100, and the other half are greater than 100.
The way the scores would actually distribute themselves would be something called a bell curve or a normal distribution.
Again, without getting into the math behind it all, what this basically boils down to is that 68% of all people will have a score somewhere between 85 and 115. What is normally considered to be genius level is above 130, though many high IQ societies only accept scores that are even higher than that.
Back to our question though; are most people stupid? Well, by definition, we now know that the average score for intelligence is 100. We also know that by definition, one-half of all people will fall below 100. So at a minimum, we can safely say that half of the people in the world (or just about any large group for that matter) are below average intelligence.
The IQ tests themselves, though vastly improved in the last few decades, are not an exact science. Results of the same person taking different tests, even on the same day, can have scores that vary by several points, sometimes more. However, when taken as a whole, the distribution will eventually fall into the bell curve pattern with the appropriate number of people in each category.
With that said, using our definition of stupid as that being intelligence, the answer to are most people stupid, is no… but half of the people are. Keep that in mind as you walk the streets, read comments, hear people speak, etc. In any large gathering, half of those people are below average intelligence… close to 3.6 Billion people on Earth… below average.