The normal distribution is the most important distribution in statistics. It describes a symmetric bell-shaped distribution. People’s heights, weights and IQ scores are all roughly bell-shaped and symmetrical around a mean. Height, for the matter of fact, has been one of the most cited and used examples to explain normal distribution. The normal distribution above is one such example.
Well, this blog is in not going to talk about the average height of boys in a class or women in a city. We will ponder upon the average height of an individual!
How do I go about measuring a person’s height? Should I use a Foot ruler or Measuring tape or a Stadiometer? Should I start measuring from the top of the forehead or from the tip of the hair?
Do I need to measure ten times or will a single measurement suffice? What scale should be appropriate or what should be the unit of measurement? How should the body posture be, while the measurement is done? Should my subject be standing or lying down? Oh wait, do I measure in the morning or in the evening?
Whew!! That’s quite a bunch of questions!! Now you might ask me, is it really that important to think about these many things? It’s just human height that we are measuring; why make such a big deal of it!
Well, let’s consider the question raised above regarding whether I should measure my height in the morning or evening. Seems stupid, doesn’t it? When I earlier mentioned average height of an individual, it did not mean the mere average of 2-3 height measurements taken at a specific time. Then what did I mean?
Did you know that our height becomes less as the day progresses? We tend to be a bit taller right after we get out of bed. This is due to the collapsible nature of the spine. When lying down, the vertebrae in our spine are spread out horizontally, which causes the spine to lengthen. As we go through the day in an upright position, the vertebrae are stacked and compressed under the influence of gravity. Our height, therefore, shortens and stabilizes as the day goes on. While it is okay to measure in the morning, it would be better to record our shortest, baseline height at a later time during the day. This is the height we spend the most time in, and the height that people know us by.
The shortest (CHANDRA BAHADUR DANGI) and the tallest (SULTAN KOSEN) met at the 10th annual Guinness World Records Day in London. They hold the records for the shortest and the tallest man living.
Shortest man living (mobile) - http://www.guinnessworldrecords.com/world-records/shortest-man-living-(mobile)
Tallest man living - http://www.guinnessworldrecords.com/world-records/tallest-man-living
Well, it is not a single measurement with which these people have been honored with the records. The strict Guinness World Records (GWR) guidelines stipulate that the claimant must be measured three times in one day by the GWR judge.
The average of the measurements is the definitive height as it is medically proven that the body expands and shrinks throughout the day.