Dog or person - the only available. It looks like a model of a production line platform, to me - something to move tools or materials or product back and forth along a bench, wall, aisle, etc. It doesn't steer. What that model looks like: a hand moves it, using the dog as a handle.
population density ? genetic preclusion to varying degrees of mental illness ? balanced diet ? i think the nature of your question vastly outweighs the possible variance in content of answer. like asking "how round is a ball?" The measure in which you rate the association to be lacking or variant from is a deviation from something we have yet to define as a norm. you need a few filter questions to establish some basic perameters. to allow yourself some easy ground, you could start with asking "why do people in modern citys seek to live minimalistic lives in segregated communities?" such a question of those you define to "be the norm" as a form of their own variance would make more logic than asking the moose why it does not eat fish like an eagle.
Btw: just recalled to memory - the Aztec Empire was about the size of the Akkadian empire, the Mayan city-state arrangement featured several cities of 50 - 100k population, and the Inca Empire was quite possibly the largest in the world at its 14th Century peak. 2 million square miles. Nobody knows how large or populous the Mississippi River basin political units were, as they apparently disappeared between the first contact with the Spanish near the Gulf and the arrival of Euros in midcontinent (good building stone is rare along the Mississippi southern basin). But if continuity of things like large ceremonial mounds are any indication https://en.wikipedia.org/wiki/File:Mississippian_cultures_HRoe_2010.jpg empire is not too much of an exaggeration.
foot note. i suspect the The Maya, Inca, and Aztecs were the 2nd era to live in the citys after a probable collapse of the civilisation. i suspect that the blood cult religion was a second civilisation that was born on the death of the builders. the sacrifices and religion was all about attempting to regain the technology & wisdom of the minds and skill that built the citys & possible plagues that decimated them. i would not be surprised if the age of the citys is twice as old as currently thought. the western industrialist slave trader mentality society is not th ebe all and end all judgement of what real advancement is. the idea of a well balanced indian civilisation living in a fairly simple low carbon manner with good plant knowledge for thousands of years quite happily is not a blight on human intellect. it may be incongruent with modern western 1st world patriarchal egos though. maybe its penis envy
