yes,
By taking testerone
a man is able to grow a beard if his dad is able to grow a beard
The best way to grow more hair on your beard is to never shave.
If an Amish man has a beard that means he is married. Once they become married the need to grow a beard.
no
You have to remember that you have DNA from both parents and it is possible you got a gene that doesn't allow for thick beards. Take a look at both sides of the family. It might be hormonal as well. You are young at 20 years old, so it is possible when you are older your beard will thicken.
Shaving a beard makes it start to grow faster. --Shaving your beard is but only a myth, some have the ability to grow a beard relatively fast, while others do not, look at members of your family and generally you will fall into some category of that sort.
I have a rather large beard and I got mine by giving up shaving
Abraham Lincoln grew a beard because an 11 year old girl wrote him and suggested it. She wrote that he would look better with a beard and it would encourage women to influence their husbands to vote for him.
Don't shave .
Testosterone
Nothing.