As I've covered recently, Joe Vitale mentioned that we absorb influences from our culture. Napoleon Hill, in his later works, described a similar scene with his "Cosmic Habitforce". All our patterns are stored in the quantum hologram - so one is able to address any pattern there. And one addresses those which are attracted to them.
If you have never set your default attitude to positive and loving, then you will attract the patterns and habits which you have agreed to through your environment.
What was interesting this weekend was to see those in my own near relatives who work with critical thoughts constantly in their own lives - and were pulling in critical comments. Positive actions would get positive responses. One for one, this continued to occur.
So the trick is to keep your own counsel, as Hill says. Hold to your own integrity and live your own life. But this doesn't mean keeping mum. As you do and say only supportive, loving and positive things, you will then bring these toward you and actually bring out the best in those around you. You have to know what you are doing and what you are wanting to achieve, to manifest around you.
One technique here is to quietly bless those around you, sending your ideal scene for them out to the Universe to manifest. What they agree with from your scene will manifest in their life, as that is what they will attract. You are just helping them, by creating a choice for them. Of course, this doesn't violate the Law of Free Will. You are just giving additional options into their life. You will attract what you want in life - if you want loving, supportive relatives, then you will have to put that ideal scene out there and also be loving and supportive in all your own actions.
That's the simplicity of handling your environment. There's a phrase I heard from Dyer (and I don't recall which of his tapes), that if you can't change the people you are with, then change the people you are with. Dr. Peale covered this with his concept of "Prayerize, Visualize, Actualize." You can and do influence people around you, primarily with your example and your own feelings. You will attract the best in people around you as you create your own positive visions and leave these to the Universe to create.
Likewise, if you say something unkind while you are tired or off-guard, it will come back to you - attract similar comments back at you/about you.
The trick is to constantly stay grateful for the good around you. And this takes practice - so practice daily.