horizon wrote:alanesq: I just wanted to stay with the contagion aspect a bit longer. Here are two quotes from the webpage that karlt kindly provided:Common cold is the most common disease
Common cold infections are so widespread that there can be very few humans who escape infection each year and most will suffer multiple infections. It has been estimated that adults suffer 2 to 5 colds per year, and school children may suffer 7 to 10 colds per year.Common cold viruses are not very contagious
Despite the fact that very few of us escape from at least a couple of common cold infections each year, common cold viruses are not very contagious. Under laboratory conditions when healthy volunteers are kept with others who are suffering from common cold infections it has proven remarkably difficult to spread infection from one person to another.
I'm still having trouble with these two quotes. A not unreasonable conclusion is that a lot of people are not catching their colds from each other.
It doesn't mean that at all. It means that most contacts don't cause an infection. Some do. Over the year you come into contact with hundreds of people carrying cold viruses; around 2-5 of them cause an infection in you. I'm not sure how you got from "most contacts don't cause infection" from "most infections don't come from contacts"; it sounds like a version of the all X is Y, therefore all Y is X fallacy.
To give you a cycling analogy - most left turns by motorists don't left hook a cyclist. But all left hooks result from left turns by motorists.