Having looked at all the reasons we are each considerably more unique than the proverbial snowflake, we now take the opposite view: You and I are just typical repetitions of the human theme, fitting very comfortably into the norm by almost every standard of measure.
Typical Bodies
We should be very glad our bodies are ordinary, and generally we suffer when they are not. The practice of medicine only works because almost every human body has the same plan, right down to the location of every tiny nerve and capillary. If you have dextrocardia (Wikipedia), your heart is on the right side of your chest, not the left. That can cause a critical delay in treatment if you need an EMT's assistance. ("I can't find a heartbeat!" "She's breathing, what's the matter with your stethoscope?")
Because we are typical from the gross details right down to the most subtle chemistry of cell respiration, we can be helped when we are sick. The Heimlich Maneuver can be taught to everyone because everyone's airway and lungs and rib-cage work the same way. (But that is also why choking on food is common enough that it is worthwhile teaching the Heimlich: everyone's airway has the identical stupid design, sharing a path with the food-way.)
On any physical measure you care to take -- height, weight, finger-joint length, microbial population of the gut, lung capacity, blood lipid fraction -- whatever doctors can measure now or will figure out how to measure tomorrow -- each of us will be found somewhere on a bell curve and almost always, comfy at the fat center part of the curve.
You and I share a body plan with everybody else and the differences between the extreme examples on any scale are really small. The difference between the tallest and shortest people is what, a factor of four? Between the skinniest and the heaviest, perhaps a multiple of six? I will go out on a limb and say that nowhere in the human race will you find a difference of one order of magnitude (10X) between the most and least of any measure. (But differences of an order of magnitude can be found for example between the largest and smallest trees, cetacians, hailstones, and lots of other products of natural processes.) Even when two human bodies differ greatly on one scale, for example weight, IQ, visual acuity or hair length, they remain near-identical on most other measurable scales.
Even when the gross details of our visible anatomy differ, the internal organs don't. There is much less variation in the size of hearts and livers than there is in body weight or arm length. The 500-pound man has a heart pretty nearly the same size as that of the 90-pound model. There certainly are differences in the efficiency of internal organs; as a pathetically feeble bicyclist I am very aware that my heart, although it may be the same size as Lance Armstrong's, is nowhere near as efficient at moving blood around. Or maybe it's his lungs that are better than mine, or his blood platelets. There is one or a few bell-curves in which Lance and I are found in the opposite tails, thus accounting for the difference in our cycling capacities. But even then, on most measures, he and I will be similar. (I wonder in which measures I exceed him? None of any external significance...)
We are all very, very similar to each other. This is unsettling to think about. One time that it becomes very unsettling indeed is when we come across a picture of a lot of human corpses: a heap of Nazi death camp victims, or a row of people drowned in the 2004 Tsunami. The sight of human bodies lined or stacked like awkwardly-shaped cordwood strips all pretense of uniqueness, leaves us knowing that our bodies, too, could be flung in such a pile and would not stand out in the slightest.
Similar Minds
Our minds, too, are much alike. No big surprise, since minds arise from the physical basis of our brains, which vary little in their anatomy. Again, we can be glad our minds are alike, because that's what makes communication possible! There could be no teaching, and no story-telling, if our minds were even as varied as our hair styles.
Philosophers worry at great and inconclusive length about whether your experience of "red" (or "hot" or "sweet") is the same as my experience of those things. How can we know? We can't. It is at least conceivable that when you and I stand side-by-side and look at a red flag, I see red and you hear (what I would call) a C#-major chord.
Possible, but damned unlikely. This is the sort of thing that philosophers like to chew on, but since the hypothetical you and I are using near-identical corneas, retinas, optic nerves and visual cortexes to see the red flag, the only practical conclusion is that your experience is very much like mine -- in this and every other physical perception.
Emotional perceptions are another matter. The brain is unique among body parts in that its whole purpose is to learn, and it changes throughout life. All our other organs aim at being consistent, and returning to a consistent state after any injury. The brain (and for this essay, I extend "brain" to include all the distributed parts of the body that cooperate in emotional responses) changes and adapts with every experience, so in the pattern of our emotional responses to life, we are each as potentially unique as our individual life histories are. You didn't grow up on a dairy farm in the Pacific Northwest in the 1940s, or attend college in the 60s or live in England in the 70s; and I didn't grow up and form my emotional patterns in the marvellous places you enjoyed. It's a wonder we even speak the same language...
But that wonder is in fact demonstrated, millions of times a day. People whose life histories are so drastically different can yet agree, cooperate, work together, fall in love, teach each other's children, manage each other's finances, enjoy the same novels, plays, and art, vote for the same candidates. Those things simply could not happen if it were not the case that all of our minds tend toward very similar responses. In mental and emotional measurements, as in physical ones, we end nestling fraternally in the fat part of most bell-curves.
In the physical realm I know that Lance Armstrong and I are in opposite tails of some distribution or other. Similarly, in mental abilities I have had the privilege of being in the presence of some really smart people. I rank as smart by some measures; well, I'm on the right-hand side of the IQ curve. But I've talked to and worked near people whose abilities were wayyy over there from me. And I've occasionally tried to teach something to people who were on the other side of the curve and been frustrated by it. So there are outliers; and perhaps the mental and emotional bell-curves are a bit flatter, have longer tails than the physical ones. Just the same, human society, human art, human culture in general could not work if we were not all very closely alike in the way we think and feel.
Alike and Different
We are each absolutely unique; we are each absolutely typical. Which is it? The answer is "yes."
Next time: the Lone Cowboy/Corporate Cog axis.