Why are some people so short and some so tall?

Answer 1

Those differences are mainly genetic, although nutrition also plays a role.

___________________________________________________________________

This is due to Human Growth Hormone (HGH)

The person's answer above is correct but definitely not all inclusive of the possible factors. A person's rate of growth depends, among other things, on the release of Human Growth Hormone (HGH), otherwise known as somatotropin. HGH is released by the anterior pituitary gland; and it's release is definitely going to be affected by such things as genetics and nutrition but other factors play a role as well, including sleep. According to the website "The Brain From Top to Bottom,"1 (TBFTTB) HGH also plays a role in metabolism and fat burning. Here's a direct quote from their site:

"The secretion of human growth hormone, which is essential for bone and muscle growth in children, takes place mainly during deep sleep, which occurs mostly at the start of the night. In adults, this hormone plays an important role in metabolism, promoting the synthesis of proteins, helping to burn fats, strengthening bones, and so on."1

How well we sleep is dependent on many factors, not the least of which is chronobiology. The above site is highly informative and gives information on various levels of understanding: beginner, intermediate, and advanced. So I would recommend it highly for learning more about the brain as well as various other things. You can also learn a bit more on John Kimball's site.2 He is a Harvard graduate and has his doctorate. The information on this site is limited but understandable for the most part. The body is a very highly complex system; so it's hard to get a short, concise, uncomplicated answer to any question on its workings. This second site is probably too concise and could afford a little more explanation. However it gives a couple of terms that can be Googled to find out more and clearly outlines the pituitary's function involving hormones, including HGH.

If you want downright complicated though, you can always go to Wikipedia.3 :) They state that HGH has "intrinsic lactogenic activity" which is suggesting that it generates the formation of lactate which is used to "feed" the brain's neurons. Wikipedia associates HGH release with REM sleep, while TBFTTB states that it is released in deep sleep, which is stage 4 (delta) sleep. I'm not sure which is correct.

1 http://thebrain.mcgill.ca/flash/i/i_11/i_11_p/i_11_p_hor/i_11_p_hor.html

2 http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pituitary.html#GH

3 http://en.wikipedia.org/wiki/Growth_hormone

---Debi62

__________________________________________________________________

Answer 2

Put basically, genes. People people have the genes to be small and some have the genes to be tall. It's like eye color. Gene for brown or gene for blue.

anybody asking this question is a dumb by nature...

Answer 3

Nobody really knows why some people mature earlier, but it probably has a lot to do with how much responsibility they have. Parents who allow their children to fail and experience the consequences of their own actions usually help those children to mature faster. Kids who are spoiled and have everything done for them may never learn how to act in a mature fashion.

Answer 4

Height is determined by a combination of genetics, environmental factors, and nutrition. Genetic factors play a major role in determining an individual's height, as certain genes can influence growth patterns. Environmental factors such as diet, health, and living conditions can also impact a person's height, leading to variations in height between individuals.