Why is it that ladies who use cosmetics largely begin to have beards or hairs on their lower chins?
The thing is that I want to know is whether really there is a connection between cosmetics and the increasing number of ladies with hairs on their lower chin.
The use of cosmetics has nothing to do with hair growth anywhere on the body. It has everything to do with hormones, and mainly, levels of testosterone in the body.
When adolescents go through puberty (both boys and girls) the immediate increase in testosterone production typically causes the growth of underarm hair, pubic hair, and facial hair in boys. I think one reason you may have incorrectly linked female facial hair to cosmetics is because we live in a trichophobic society (the fear of body hair), and many women use extreme beauty regimens to remove or cover unwanted body hair.
The fact remains, as women get older, almost all of them are likely to develop hair in "unwanted" places, such as the upper lip and chin. Many experience the loss of head hair and an increase of body hair as a result of birth control or pregnancy. Others find that the hair all over their body changes with age (gets thicker, thinner, goes curly or straight, turns gray). It is simply the result of varying hormone levels that naturally fluctuate with age.
A simple search engine inquiry for hormones and hair will produce hundreds of informative articles discussing this relationship, but I do not think you will find the same results if you seek to prove that facial hair growth is caused by cosmetics.