History TookALevelInKindness / LiveActionTV

* ''Series/HomicideLifeOnTheStreet'': Tim Bayliss starts off as an almost unbearably self-righteous and whiny RabidCop. By Season 3, he's mellowed out into a NiceGuy, and more attention is drawn to his compassion and sensitivity. A large part of this is because, for the first two seasons, Bayliss's colleagues treated him like crap for being the rookie, which of course made him more prone to lashing out and he was having his trauma from the sexual abuse he experienced during his childhood dredged up by the Adena Watson case. In the third season, he had moved past his failure to solve the case and mostly been accepted into the unit, resulting in him gaingomg a better temperament.

** The Doctor. Yeah, you might know him now as a goofy fun-loving guy who likes to save innocents, but his first incarnation wasn't nearly as nice. His [[Recap/DoctorWhoS1E1AnUnearthlyChild very first story]] featured him kidnapping two humans because he didn't want them exposing his secret, and he often showed no qualms about killing people they encountered. Part of the change was definitely deliberate, as the writers wrote him becoming softer and kinder over his run, but part of the change is due to the change of the show's premise. When the Doctor started out he was a mysterious presence to intrigue the viewers and the show's ''real'' protagonists, the companions Ian and Barbara, whereas now much of the Doctor's backstory is known, and he often functions as the main hero.
*** Note that the Jerkass persona can be chalked up to EarlyInstallmentWeirdness: the Doctor is only downright malicious in his first three stories and softens up afterwards, and his negative traits almost entirely disappear by the end of his first series. William Hartnell spends most of Season 2 playing an eccentric loveable grandfather figure who is constantly giggling and calling people "my dear boy". As evidenced in [[Recap/DoctorWhoS30E16TheWatersOfMars "The Waters of Mars"]], nasty things happen when the Doctor doesn't have a companion. Maybe the Doctor needed Ian and Barbara's influence to take a level. One Eleventh Doctor comic featuring Ian as companion had the Doctor explicitly say that Ian and Barbara were his influence to become a prosocial force rather than just a selfish old man with a time machine.
*** It is made rather explicit in the new series that the Doctor needs his companions as a sort of MoralityChain. Amy Pond lampshades this after the Doctor's first instinct is to go for the kill to punish a war criminal. "This is what happens when you're alone for too long."

*** His twelfth incarnation starts out as a cold, cynical PragmaticHero who openly wonders if he is "a good man" anymore. A few seasons worth of CharacterDevelopment and he's mellowed into a much kinder, if still irascible, man.
** Romana decides to spontaneously regenerate to serve as a symbolic change for her doing this. Her old self was smug and a bit of a pain, but when the Doctor's influence on her character made her realise this was not a good way to be, she regenerated into a new body in which she was a lot more amiable and something of the Doctor's DistaffCounterpart.

** From a specific episode of the original, Elaan from "Elaan of Troyius".
** When introduced in ''Series/StarTrekTheNextGeneration'', Q is an adversarial omnipotent entity who holds humankind in contempt and would love nothing more than to see the race wiped out. Over time, however, his interactions with Captain Picard and the crew of the ''Enterprise'' cause him to develop a fondness for humanity. While he still remains fairly unpleasant to be around, his demeanor changes from a JerkassGod to a TricksterMentor (who still enjoys making Picard squirm from time to time).

*** Jack the genetically modified savant is introduced as a borderline sociopath who threatens to snap Sarina's neck if Bashir doesn't fix an annoying sound in his quarters. In his second appearance, he and the rest of his savant crew go to considerable trouble to smuggle Sarina back onto the station to force Bashir to finally cure her catatonia. While still hyperactive and sharp, he's mellowed out considerably. His one moment of rudeness is insulting Sarina's marble-mouthed speech after she's cured, but he promptly leads a singalong to solve the problem, much to everyone's delight. All that time at the Institute between episodes must have done ''some'' good.

** ''Series/StarTrekDeepSpaceNine'': Jack the genetically modified savant is introduced as a borderline sociopath who threatens to snap Sarina's neck if Bashir doesn't fix an annoying sound in his quarters. In his second appearance, he and the rest of his savant crew go to considerable trouble to smuggle Sarina back onto the station to force Bashir to finally cure her catatonia. While still hyperactive and sharp, he's mellowed out considerably. His one moment of rudeness is insulting Sarina's marble-mouthed speech after she's cured, but he promptly leads a singalong to solve the problem, much to everyone's delight. All that time at the Institute between episodes must have done ''some'' good.

** Dr. Rodney McKay was introduced as a [[JerkAss Jerkass]] [[InsufferableGenius insufferable genius]] in [[Series/StargateSG1 SG-1]], acting as a [[HateSink hate sink]] for the audience to detest. When he became one of the main characters in the spinoff [[Series/StargateAtlantis Atlantis]], he still retained that arrogant and obnoxious personality, but gradually became more and more sympathetic, risking his life on multiple occasions to save others and genuinely bonding with the team.

** Daario has certainly mellowed out and acts relatively less hedonistic since being recast. The arrogant bad boy characterization has been toned down considerably.

* ''Series/OneTreeHill'': [[JerkJock Nathan Scott]] over the course of season one, and [[TheCheerleader Brooke Davis]] over the course of seasons one and two. They end up two of the nicest people on the entire show.