The 4 basic types are the extremes. For example: the Natural types (dominant adrenals)
are wide and strong looking, built for endurance. In addition to their "good" personality traits, strong, generous, focused, they are also arrogant, angry and avaricious in their first response to events and people. This tickles my funny bone because I have a dominant A side and I love that A words describe it. I'm remembering "My Little Pony Tales" on TV. One annoyed little pony says to her friend, "She thinks she knows everything." The one they're talking about overhears and says to herself, "I do know everything!" That's me.
All of our strong points have an equally negative side. It's okay to have these "bad" first impulses because we can learn to take a deep breath and choose a better response - so our friends and families don't give up on us. It's also interesting that our best talents often irritate them.
Gamin types (dominant pituitary) are short, small and smart in a very detailed analytical way. They are also shy because their Slow Left/Slow Right brain style needs more time to process a myriad of details. (Love all those S words, short, small, smart, shy, slow.)
Dramatic types (dominant thyroid) are built for speed - they don't have time to consider the consequences of their actions so they often find themselves in trouble of one kind or another. (So tall, trouble, - what are T words for witty, willowy, etc.?)
Romantic types (dominant gonads) may end up in emotionally demanding caregiver jobs (teaching, therapists, etc.) because they are so empathetic. But even they can only do so much.
If there were only basic types, life would be a lot more hectic with extra drama on all sides. Anyway, in addition to these, mother nature made 4 classic types and 6 combination types.
The 4 classics are more even, less extreme in their actions and looks.
The Classic (Natural Classic) is an A type who has balanced responses to life built in and also a more balanced body shape because, although her adrenals are dominant, the other three main glands are almost equally active as well: the thyroid (short bursts of physical, mental and emotional energy), the pituitary (sustained mental energy) and the gonads (ovaries in the case of women - for sustained emotional energy).
It's as if nature started with a Natural type, A, but made her slightly smaller around and shorter from a Gamin influence; with some angular edges and maybe sl. wide shoulders or sl. long nose from the Dramatic; perhaps slightly more waist and more padding on the rear from the Romantic with weight gain. That's the Classic, a balanced Natural type.
As a culture we've always recognized and admired the Classic Types. We like middle of the road beauty, symetrical features and figure. Not too tall, not too rounded or angular. There are many other types of beauty that go unrecognized and unappreciated, mostly because designers emphasize styles for one type at at time in trying to give us something new to wear. It may be years before they get around to your type, if at all. Until then you'll be wearing someone else's styles and not looking your best.
Then we also have a Gamin Classic Type, a Dramatic Classic and a Romantic Classic. Each has a dominant side that is balanced by traits from the other three types.
For a Gamin Classic, nature took a Gamin type and made her slightly more sturdy
with some width from the Natural (or Dramatic) and with perhaps a larger bust and full lips; from the Dramatic maybe a sl. longer nose or arms or fingers/toes; and
from the Romantc perhaps a straight line between the upper/lower lips, sl. more waist
(because of having more hips), more rear padding with weight gain, small hands/feet,
a sl. wider jaw (also a Natural trait). That's the Gamin Classic; balanced with a few traits from the other 3 basic types. Slightly wider, taller, etc. than the Gamin.
The same thing is true with the Dramatic Classic and the Romantic Classic. Nature started with the basic type and added traits from the other three types.