Answer:
Modern IQ tests run off of a statistically normalized distribution. 100 is normal intelligence based on the average intelligence of the group. It also uses a spread of 15 per standard deviation (e.g. if someone is 2 standard deviations above the average, they have an IQ of 100 + 15*2=130; similarly, if someone is 2 standard deviations below the average, they have an IQ of 100 - 15*2=70).
Trade enhances economies through the creation of jobs, and the sale of the items. Can't have an economy without buying and selling. Trading is usually a positive thing, that being said certain types of trade can actually hurt jobs. For instance, when more modern clothing was invented and sold, lots of people selling animal skin clothing and such probably had to find a new way to make a living.
