Cowboys in westerns always have standoffs because the one who draws first attempts murder, to draw second is justified self-defense
Everyone is armed all the time and that's normal, but to draw a weapon is an overt hostile act. A standoff therefore is a game of chicken because both want to kill each other and you want to draw first to have the highest chance of surviving, but even a bandit will hesitate to add a felony murder charge to their rap sheet. The whole town serves as witness when there is a pair of eyes behind every shuttered window. The hero always draws second, both demonstrating his superior skill and speed by defeating the opponent even at a disadvantage, and getting away with murder scot-free.
So what does this mean for Western gunslingers? Is it always better to draw second? Well, not quite. Welchman also found that the 21 millisecond benefit of reacting quickly was totally overwhelmed by the 200 milliseconds it took to react in the first place.
Of course, ethics committees might frown on scientists duelling with the pistols in the name of discovery, even if the people in question were graduate students.
Yeah, nah. A standoff looks cool, adds tension, gives the goodie and baddie time to talk or to be silent (menacingly). But apparently they weren't used much irl. From Wikipedia:
That's what I used to think as a kid - westerns standoffs are an outgrowth of Old World duels, a formalized custom performed by traditionalists, even the baddest bandit secretly being a gentleman at heart. The showerthought here is that the order of events is also perfectly explained by taking legal considerations of justified self-defense into account.