Your height and weight as you grow is determined by internal and external factors. This can result in a significant difference in growth patterns among children around the world with differing socioeconomic statuses and genetic patterns. Although growth is determined primarily by the amount of growth hormone the human body produces, the production of growth hormone can be altered under certain circumstances.
The "British Journal of Preventative and Social Medicine" states that children with a lower socioeconomic status or children from large families often grow more slowly, and thus are smaller and lighter than children from more privileged homes. The presumed assumption, therefore, is that these children lack some substance, possibly nutrient-related, that is more plentiful in wealthier homes. Nutrient-related or not, this trend continues even in America, as the children of professionals are typically taller than children whose families earned less and ranked lower on the social scale.
It’s no secret that your height is directly related to the height of each of your parents. Even if you are significantly taller or shorter than your other family members, the genes you inherited from your mother and your father contribute to your growth. According to Anne Tecklenburg Strehlow, a geneticist at Stanford University, scientists estimate that there are between seven and 20 genes that could influence human growth. Thus, the growth patterns of children within the same family may differ considerably due to each child receiving a different combination of genes.
Individuals born with or who develop pituitary tumors may experience different growth patterns than they would otherwise. According to Dr. Daniel Kelley, a neurosurgeon at the John Wayne Cancer Institute in California, a tumor on the pituitary gland could cause the gland to release larger than normal amounts of human growth hormone, resulting in acromegaly--often known as “gigantism.” Dwarfism, by contrast, is usually caused by a genetic mutation rather than a pituitary tumor.
Exposure to certain medications can inhibit human growth patterns and result in an individual growing more slowly or never reaching his full height. An example of this is a 2007 CBS News report stating that the attention deficit hyperactivity disorder drug Ritalin has a growth suppressing effect on children, causing those taking the drug to be, on average, shorter and lighter than peers of the same age.
Children who develop a severe illness in infancy or early childhood are more likely to demonstrate inhibited growth patterns. Historical records demonstrate that individuals living in areas riddled with infection and disease in the 18th and 19th century grew to a shorter height than those who were not exposed to severe illness. In addition, once technology improved to a degree where such illnesses could be successfully treated, human height patterns significantly improved.