It's not just serotonin either-most neurotransmitters can cause anxiety or anxiety like symptoms, and in some cases an over-abundance of a chemical can lead to anxiety. So it does appear that you can develop it without experiencing a stressful life.
Howard Heinzl (1918 - 1989) With regard to blue American Staffordshire Terriers, any breeder that believes that a blue American Staffordshire Terrier is some how more valuable than the other recognized colours, is not only deceiving themselves, but they are also deceiving their customers.
The Staffordshire Terrier is an all-American breed that is often revered for its robust and sporty trademark physique. The breed was first officially acknowledged by the American Kennel Club back in 1936, although it has a history that dates back to the 1800s.