i was reading something very interesting right now about thoughts. the author, swami vivekananda, says that each thought every person has creates a pulsation, a ripple, a wave- and can travel as does light for hundreds of years.
he says each thought, therefore, has an effect on every other mind- but the minds that will be most affected are the ones that are vibrating on a similar level.
for example, if someone is helping someone, doing something positive, this pulsation of the kind thoughts will have a stronger effect on the people who are having similar thoughts, and as a result kindness is enhanced in all of these people. that is why people who constantly think and do good are likely to continue thinking more positive and having better experiences. they are constantly increasing this tendency in each other every time someone thinks positive. the strenghtening of this aspect in people leads to more positive thoughts and actions, and the enhancement of these leads to more good... etc.
he explains that is the reason why evil doers continue becoming more evil- because each time an evil thought is released, this person and all others who are thinking alike will automatically be "strengthened" in those thoughts. so it is only natural for more evil to result of this.
so that leaves me thinking we should be more responsible with our thoughts because we are constantly leading ourselves and others to be better... or worse!