What Is Intelligence?
Society has totally different views on the word 'intelligence'. Some assume intelligence is something you are able to measure with a test. Others suppose your education level represents your intelligence. I don't agree. I don't think any test or where you have been can measure anyone's advanced mind.
Some individuals see foreigners as 'less intelligent'. This entirely depends on the difficulty it takes to speak to each other. It's tougher for some people to speak to us as English isn't their first language. However, some say this individual may be a 'stupid foreigner', despite the fact that they may be very smart.
Also, difficult and unfamiliar ideas are hard to explain to others. Maths is something that some find tough, it's not because they're stupid, but that there are several complex concepts in Maths that come naturally to some, and takes longer to grasp for others.
Communication is typically the factor in which we regard people as smart or less intelligent. Whether it's trying to communicate where the closest fuel pump is to describing an advanced Maths equation, this is the point of judgement for many humans.
A Practical Example
You may have a dodgy boiler; so you may call up a heating engineer. They will come to your house, diagnose and fix the matter within minutes. If you ask them an explanation of what modifications they have made to your boiler, you almost certainly wouldn't understand much.
This is not because you're stupid, but because the engineer sees you as someone who is familiar with heat engineering and boilers. Therefore, he would use engineering language to match your 'intelligence'.
The engineer isn't superior to you. He simply mistook you as a peer, not one who is unfamiliar with engineering. This, of course, doesn't make you stupid, however, less informed in that field.