There is a certain art to ruining a conversation. I mean really ruining it. Not just making perverse or awkward remarks or speaking too much or too little. Often people can ruin a conversation by doing all these things or by treating the other person as merely an outlet for their ideas or someone to compete with for attention.
However, really ruining a conversation involves taking any subject and draining it of all meaning. It is important to be humorous, but often when people do this they think they are actually being quite deep. When people think it is profound to be stupid they have an easy way to pretend that they are having real conversations. It is easy to conceptualize this but much more difficult to illustrate it.
A good way to do so is to use an example from the TV show Seinfeld. Consider this quote from an episode called "The Fire" where George explains to Jerry his reasons for running out ahead of everyone else when a fire broke out at a birthday party.
Jerry: So you feel 'women and children first' in this day and age is somewhat of an antiquated notion."
George: To some degree."
J: So, basically, it's every man, woman, child and invalid for themselves."
G: In a manner of speaking."
J: Well, that's honest."
G: She should be commending me for treating everyone like equals."
J: Well, perhaps when she's released from the burn center she'll see things more clearly."
This particular quotation is intended to be humorous and to an extent it is but only because of the last line. What George uses as his rationale is incredibly stupid and ridiculous and it is Jerry who points it out. If Jerry had told George how much of a terrible human being he was the only sound after that joke would be from the laugh track. This is an excellent example of this way people have of saying absolutely nothing when they think they are saying something profound. Does George explain why he thinks that women and children first is and obsolete idea? It may seem like pouring over a quote from a TV show is a waste of analytical energy but people really do talk like George, Jerry, Kramer and Elaine.
Why then, you ask, do we not find ourselves constantly thinking about the ridiculous things other people have said? Well quite simply, we do not listen. All too often people simply speak to hear their own voice and pay little attention to what other people are saying. This is one of the reasons that Seinfeld speak exists; people do not pay attention to what others say, and are so preoccupied with the fact they're talking they pay little attention to what they themselves say. Often what happens is that when people are discussing serious subjects, their desire to be a part of the conversation overrules their impulse to think about what they plan to say. The end result is that people say things that are superficial, stupid, redundant and rather pointless.
A good way to stop a conversation is to say something that can provoke little or no further thought. A simple bland statement of fact is a good example (unless you are using it to support and argument). People often think that a person who says whatever they think should be commended for their honesty. Quite the contrary, however. People who speak excessively without regard to the depth and weight of their argument should be chastised instead of being applauded for being novel and superficially clever.