Getting tipsy is more than just a simple equation of “Insert booze, receive stupid behavior”. There’s some complicated chemistry at work — especially when you begin to factor in the stuff you mix your alcohol into. For instance, the sugar in soda actually prevents your blood stream from absorbing as much alcohol as it otherwise would. Which means, as Allison Aubrey explains at NPR, your choice of mixer could be the difference between a blood alcohol level that is within legal limits and one that is most decidedly not.