Interesting start Patty - quite a few questions in there.

Here is one take on mate selection among humans:

Diversity and disparity of apparent feminine attractiveness induces regulation of masculine competition.

I've said that before, recognize that apparent or superficial visual attractiveness does not strongly influence reproductive success. That in the general sense, not in the special or individual sense.

The basis of the claim is that regulation of competition occurs in numerous forms. To quote me-self "Any movement, whether individual or evolutional, away from combative competition and towards ritual and or display is regualtive. The function of society is regulation of competition."
So, a culture of dominance as exhibited by most primates acts to regulate competition. This benefits the dominant members most directly by reducing the level of combat. For instance, among many species that have harums the life of the dominant male, or harum master, is surprisingly short, sometimes measured in weeks after achieving dominance.
Humans do not exhibit a culture of true dominance. I characterize human culture as, diversity and disparity of apparent competitive capacity induces regulation of competition. Also, increased selective variability allows increased genetic diversity.
Humans are the great socializers. Also, utilize acquired characteristics to the greatest extent.
Diversity and disparity of relevant (competitive-selective) characteristics are both active and passive, by my definition, active traits are acquired, passive traits are inherited. So superficial attractiveness is a passive trait, (historically at least) personality adaptations to socialization is active; but, the impulse to socialize? Now it starts to get tricky.
And even trickier, the issue of intelligence. I'll give an example.
About a month ago I was shuffling out in robe and slippers with the trashbin to the garbage can in the brisk early morn when I was spied by a stray cat, feline persuasion. She made a rasping sound of mewish quality and came straight toward my slippers, much relieved, it seemed, to have come upon a human. She was quite starved.
Now, I'm used to barnyard cats who give a quick glare and scatter at your approach, they eat the food you put out, catch rodents, and generally regard you with contempt, unless they feel like it.
I didn't regard this as a very bright cat, but then, it turns out, she's a total indoor cat. When you come in the front from the porch she's typically excited then turns and walks awayfrom the door, into the room. Unusual from my experience. observing her behavior it seems apparent that she was a little old man's pet. Everything she does and likes reflects an old man's diet and habits. Loves the Lazyboy chair, grumbles if you move her, sits up and begs for table scraps. I have to discourage begging however. Yesterday, I was sort of cheering a particular Ftball team, she was on the Lazyboy, I was on the couch, the team made a big blunder, about all I did was roll my eyes in exasperated silence. What did she do? She groaned. A perfectly timed horse moan of dispair. A sound I've never heard come from a cat before.
So is she the dumbell I called her at first impressions? Or is she perfectly attuned to her providers moods?
My expectation, returning to human personality is that, with the exception of some identifiable disorders, genetic or injury induced (etc.), most humans have basiclly equivalent intellective capacity. But a wide range of expression of it.