Gambling can change the attitude of someone who tends to become a stubborn person, and indeed this can of course have an impact on their relationships, whether it be family, partner or friendship relationships, where they will experience the bad effects of gambling, which can make them change as well.
Can gambling actually change someone who is bad mannered for good instead of getting them more complicated in their wrong doings, same way we can see gambling as a means of getting ourselves attached to something that could get us being occupied than having much time on unnecessary things, we should also be mindful of not allowing irresponsible gambling to affect our personal relationships.
There are instances where a bad mannered person become tolerant or giving. That is when he won a huge amount of money from the casino. This takes away frustrations and worries making the bad person in good mood but it is temporary. A person's attitude or characteristics can only be altered temporarily, since whatever the persons core personality is will always shows after the effect of being in a good/bad mood fades away.
we should also be mindful of not allowing irresponsible gambling to affect our personal relationships.
But once a person become irresponsible whether it is in his gambling activities or on other things, it already affected his personal relationship with other people. Like when an employee was caught being irresponsible, his relationship with his boss will deteriorate. In a family, when a member become irresponsible of his choir assignment, his relationship with his family is already affected, same goes with irresponsible gambling, his relationship with people around him is already affected. Like when one is hooked and spend all his time on gambling, his time spent on his family will be affected and his family will view him as irresponsible one. From that negative relationship is developed.