Study has indicated that the body's reaction to diseases can change personality.
Autism in general and Asperger in particular seem to have a strong component of not understanding or being able to read other peoples emotions and thinkings. This sounds a lot like a pheromone reading problem.
The existence of pheromones itself, the fact of their existence, implies that some people will have associated deficiencies. There will be two forms: one where people don't send pheromones out; another where they are unable to read other people's pheromones. Of course, they could be combined in the same person, but would not necessarily have to be.
Also, pheromone reading/sending may exist at multiple strengths. ie, one person may be able to send stronger messages than another one. The same applies to reading.
Everyone knows that family ties are strong. There is the old proverb "blood is thicker than water" [meaning that family steps in ahead of religion(water refers to baptism)]. Families seem to be willing to help one another, put up with one another, and in general support each other in ways which would not occur between strangers.
Any binding relationship like this between people, which has few, if any, other observable causes probably point to pheromone generated relationship. Certainly the common years-long mutual exposure to one another's pheromones would exist in a family.
Another check on this would be the results in broken families. Very seldom can any strong family relationship exist where families have been torn apart. Look at the effects of divorce on the children (not to mention the husband and wife). There appears to be a universally noticed lack of being accepted, of being part of a family. Again children raised with a single parent seem to notice the lack in their lives, in the differences between them and others.
Diseases are known to affect people, even after the person has recovered from the disease. Aside from paralysis like in Polio and blindness in Ochoreisis there are olso shown to be mental effects. For example: http:/www.natur.cuni.cz/~flegr/publpar.htm There is evidence that rats are changed mentally by cat diseases that they catch - the result is that they are not afraid of cats!
Now vaccinations are simply artificially induced disease effects upon the body; so it would imply that vaccinations could also cause changes in people. Specifically it would be nice if someone would study mental changes after any given vaccination has been taken.I have seen no evidence that people are looking at such questions. It seems to be taboo to ask. Perhaps the medical establishment is afraid to see the answer, for fear that people will no longer take vaccinations.
Cities are said to "not reproduce themselves", ie the birth rate to women in a city is not sufficient to replace the natural death rate of a city.
Now some of this may have to do with an increased death rate in a city, since sanitation appears to be a relatively late invention. Of course, human caused deaths - accident, murder, strife, etc - would also be higher in a city. But there would also appear to be another problem.
Female fertility appears maximized for a unique male set of pheromones. Thus, a woman with a lot of unique male hormonal "triggers" would have a higher fertility rate than one contending with multiple non-unique triggers. Families in farming, faming being a "solitary" occupation, would generally have a higher fertility rate than families in cities.
Pheromones were first found in insects (I believe). These are chemicals given off by one individual to which another idividual has an involuntary reaction. Thus a female moth will give off a pheromone which a male moth 2 miles away will detect and fly towards. Most work done on pheromones has dealt with sexual matters, but there is no reason for pheromones to be limited to sex.
Animals are known to use pheromones, again especially for sexual attraction or communication, but probably also for anger matters. Think of two bulls in combat. There appears to be pheromones each telling the other "I am better" Then when one quits fighting, the other lets him go. Obviously the pheromones have changed!