What is "Tall"?
Height Is all relative. No matter how tall you are, there will always be someone or something taller or shorter than you are.
"Tall" is a description
As a descriptive term, tall is very subjective and relies on the context in which it is used. Even a 5ft9 man can be considered "tall" when he is surrounded by people shorter than he is, but that still doesn't negate the fact that in the United States he would be a statistically 'average' height for a man.
"Tall" is how you measure up
There seems to ba a wide spread or systematic tendency to overestimate height deviations above the mean. This has been widely observed in people's misestimation of the height of very tall people-- a 6'6" man is thought to be "seven feet tall", or a 7'1" basketball player is said to be "eight feet tall".
American Indians in the northwest had a particular method of measuring the height of an object. They would walk away from something for which they wanted to know the height, say a tree, until they could see the top of the tree while they bent over and held their ankles and looked back between their legs.
Then, they would walk back and count each step as they returned to the tree. The number of steps they counted was the height of the tree. This method assumes the object measured is vertical and each step is about a foot.
Shadow Ratio Technique is a bit more accurate if you take a reference stick and measure it. Place the stick vertically in the ground and measure the shadow of the stick.
Next measure the shadow of a tree or a person and calculate the height with a ratio by cross multiplying.
"Tall" becomes an identity
As a description then, the label "tall" is incumbent upon context. But what about "tall" as an identity? As an identity, it would mean that a person must come to the conclusion that "essentially I am tall regardless of context." It's a subtle difference between a label and an identity because one can always say, "I am tall" and mean either application. To consider the label tall as an essentialist identity, one has to identify strongly with a taller body to such an extent that (s)he would gain a deeper sense of belonging from other tall people.
It's a tall thing, you wouldn't understand
Perhaps the seeds of a tall identity are planted everytime someone feels a deep level of frustration at the disconnect between their taller body and a world made by and for other body types. Height is only a factor in a limited range of interaction. Clothes shopping seems to be the biggest one tall people complain about most. If you can go into any store in the mall and find things to wear, then you're not essentially tall even if you like to use the label 'tall' to describe yourself.
Self Concept Fluctuates
How a person relates to his or her height changes over time with changes in lifestyle, maturity, self esteem and self concept. A healthy posture might be anathema to a tall teen that just wants to blend in but as a tall adult, the same person will stand up straight, tall and proud.
Because of the bell curve used to compare height, 90% of the population is somewhere between 5 ft 4 in and 6 ft 2 in. Anyone onver 6 feet tall is considered "tall" and the top 5% of the population that are taller than "tall" seem to be statistically insignificant to most demographers.
Judging by government safety regulations and industry's standardized sizing, everyone 6 ft 4 in and over is considered statistically irrelevant. When allocating space for car, bus, train and plane passengers, and considering life-jackets or other emergency equipment, people over 6ft4 are ignored completely.