Warning! Spoilers ahead for Young Sheldon season 5.
Sheldon might be closer to his mother, Mary, but Young Sheldon proves that he unconsciously takes after George more. Prior to Young Sheldon's debut, The Big Bang Theory was only able to show the socially-inept genius' relationship with his mother. Clearly, the pair had a special bond, with Mary (Laurie Metcalf) being partial to her middle child despite claiming that she loved all her children equally. Yet, adult Sheldon (Jim Parsons) also inadvertently adapted some of his dad's characteristics and even listened to some of his life lessons, and the young version of Sheldon (Iain Armitage) in Young Sheldon proves it.
Outside of Sheldon himself, Mary was the first Cooper family member and Young Sheldon character who was also in The Big Bang Theory. Leonard (Johnny Galecki) asked her to come to Pasadena after Sheldon got into trouble at Caltech with his boss. Despite her outdated beliefs and inappropriate comments, it was obvious that she loved her son dearly. Even as Sheldon started a tantrum, refusing to fix his conflict with his superior at work, the Cooper matriarch found a way to convince him to do the right thing. This was the nature of their relationship throughout the original series which is reflected in their dynamic in Young Sheldon. Before the prequel spinoff, however, it was unclear what kind of relationship Sheldon had with his dad as George was already dead by the time of The Big Bang Theory.
Due to Sheldon's less-than-kind comments about George in The Big Bang Theory, it was implied that they had a difficult relationship. While that was inevitable given George's cheating scandal, the pair is currently quite close in Young Sheldon. In fact, the spinoff continues to reveal that the socially inept genius takes after his dad, George (Lance Barber), more than his mother, Mary (Zoe Perry), albeit unconsciously. In Young Sheldon season 5, episode 8, "The Grand Chancellor and a Den of Sin," Sheldon struggles with the idea that everyone lies after he's duped by East Texas Tech's president into believing that a so-called "Grand Chancellor" exists. Wanting to make this a learning experience for his son, George explains that sometimes, people lie to protect others from getting hurt. Sheldon is skeptical of the idea, but The Big Bang Theory proves that the lesson stuck with him as he lied to spare Penny's (Kaley Cuoco) feelings during their early days of friendship.
In The Big Bang Theory season 1, episode 10, "The Loobenfeld Decay," Leonard initially lied to get out of watching Penny sing at a showcase. Sheldon was uncomfortable with the idea primarily because he didn't think that Leonard's lie was airtight enough. So, he came up with a more elaborate one that almost sounded too ridiculous. Sheldon even went as far as actually backing up his made-up story by bringing small-time actors. It wasn't exactly necessary for him to be that invested in staging their bluff. Sheldon was usually indifferent to other people's feelings; he couldn't care less if they were hurt by what he said if what he said was logical. But after Leonard essentially repeated the same lesson George taught him in Young Sheldon season 5, Sheldon's stance on the matter changed. Perhaps he remembered that his dad taught him the same lesson when he was younger and decided that it's actually worthwhile advice.
For now, George and Sheldon's relationship in Young Sheldon is still good. But it will likely significantly deteriorate in the upcoming seasons as the sitcom starts to delve into the Cooper patriarch's cheating plotline. This could explain why adult Sheldon only had bad things to say about his dad in The Big Bang Theory despite having a fairly great dynamic with him in the prequel.
Young Sheldon airs new episodes Thursdays on CBS.