Oh, I think the writers gave us some insight over the years into how and why JR's mind ticked the way it did.
I don't know if he was technically a sociopath -- some feel he was too "soft" in certain ways, but that's a mistake. Terrible, diagnosable people can often engender unwarranted sympathy because they may seem forlorn or vulnerable -- and that tells you next to nothing about their humanity, such as it may be. That forlornness is often over their inability to control other as thoroughly as they'd wish.
Clearly, JR tended to objectify people -- everybody was there to serve JR in some way. That sort of narcissism is just fundamental to someone with JRs value system, especially when he has all the resources to back up his 24/7 selfishness. And that unwavering selfishness is what, regrettably, others see as "strength" in a figure like JR Ewing; his total and unapologetic focus on himself is admired for the same reason bloody dictators are so admired by many: they are without internal conflict, at least in terms of how it affects their goals and their actions.
Remember, people don't tend to want to be better than they are, they want to be worse than they are -- only with greater efficiency and success.
How much of a role did his parents play in how JR turned out? It's anybody's guess.. There are certain things in all of our personalities which are innate and hardwired, and others which are environmental --- nurture versus nature. With JR, I doubt how much effect Miss Ellie could have had on him; she beats herself up for "letting go too soon" but with a daddy like Jock Ewing, and a chauvinistic environment like Southfork/Braddock/Dallas/Texas, just how much could Mama really do to save JR from what he became?
Then there's Jock himself, By the time we met him, he was sweet (well, semi-sweet) grandpa, but one assumes he was
much worse in his youth, and he even alludes to as much a couple of times in the script. Anything is possible in Jock's past (and I'm not sure I buy into his anti-Klan history that THE EARLY YEARS prequel tried to sell us in 1986, but if that's what the writers say then that's what the writers say...). In contrast, JR was just a spoiled rich kid whose job was to maintain the family's wealth as opposed to building a business from (below the) ground up, which requires a different kind of focus, and perhaps even a different kind of ruthlessness.
But the oil baron who-never-quite-grew-up persona was reflected even in JR's early wardrobe: a little boy in a grown man's suit. And that didn't really change until his beloved daddy had died and JR no longer had to scheme around Jock's nose and manipulate behind his back.
Suffice it to say, while Jock laments that he taught JR everything he knows, he indeed never taught him when to stop. And with someone as Mephistophelesian as Jock Ewing, why would he ever even think to teach his eldest son "to stop" before it was much too late?
Gary and Bobby had the same father, and they couldn't have been more distinct from one another. But all of the sons were profoundly affected by their parents' issues and behavior. So some of their susceptibility to react one way or another is inborn.
Psychiatry tells us that empathy is taught not by the mother -- no matter how patient and loving she may be, but by the father or father figure. And how much empathy did Jock have to convey, or parlay, to Junior? Well, we see the result.
Even Jock's will and its pointless codicil was destined to rip his family apart, no doubt to "toughen" them up even further after his death. And the perverse "mysterious letter" to be opened after the year-long contest simply guaranteed JR's place at the head of the company
anyway! If JR won the battle, he ignores Jock's letter and takes it all; while if Bobby wins the contest, he respects his father's wishes in the letter, shares the company with is big brother, and JR continues to run circles around Bobby as per usual.
The patriarch does these kinds of things to his family for decades, even post-mortem, and all they can do is worship him for it.
I mean. my God. Watching the shenanigans at Southfork may have been entertaining, but you do not want to be a member of that family, that House of Ewing.
