Can one player tighten up a game?

A friend and I usually frequent a very nice poker club in our area. The games there are always loaded with superloose "madcappers" who make the pots great for the patient player(of which there are few). We decided to bring my brother, who is a somewhat decent player, but tends to be a loudmouth at the table. Well, as usual, when we were all finally seated at a great table full of fish, he starts spouting off odds and probabilities. He made fun of a few players for their choice of starting hands and belitted others that made silly plays. After about an hour, my friend and I started to realize that the table had tightened up like a snaredrum. The pot sizes had dwindled drastically and no one was talking except for my brother. Did this sudden change in game type happen as a result of my brothers stupidity? Should I play on a table with him again and risk the same fate? Can one player, reminding everyone that this is a strategic game ruin the table and make it almost unprofitable? All comments are appreciated.

Thanks,
PokerPrince