Why Are Men's Buttons Opposite Women's Buttons In Clothing?

It's an age-old question! From our fashion history background, the default answer was always this:

Men dressed themselves, and conventionally they buttoned their clothes left-over-right, meaning the buttonhole side of the fabric lapped over from the wearer's left. But women had servants to help them dress, and because the servant was facing the wearer, they needed an opposite closure to match their opposite perspective.

Claudette Colbert dressing herself quite easily in Clark Gable's pajamas, circa 1934.

This doesn't quite hold up when you realize men had butlers, but maybe those man-servants never attended a gentleman in his dressing quarters. Also, when I use my own hands to button or unbutton a garment as a servant would (whether the item is men's or ladies'), I don't feel a preference either way. But maybe that's just me. And this custom doesn't account for left-handedness, but in the days of its origin, I doubt many people were accounting for that.

Also, consider the fact that, at various points in history, women wearing obvious closures of any kind were considered to have looser morals, because that line of buttons showed just how to gain access to what was underneath. Why make it easier to undo a blushing beauty's buttons by placing them in a convenient way for her paramour, especially in times puritanical?

I checked through my references here at Vintage Vixen for any notes about buttons, but I couldn't find any. I have several books on male & female differences in fashion, but they omit this fundamental difference, which I thought was interesting. It also seems to indicate that this was a custom created out of a functional need, not a sexual differentiation.

So I looked around online. There are many ideas about this historical conundrum, and in addition to the theory above, here they are in summary:

• Men needed their coats to close with opening toward the wearer's right, because they pulled their sword from their left hip. If the coat opened to the left, the butt of the sword could get caught in this opening.
• Women tended to carry a child on their left hip, and they nursed by opening & closing their blouses with their right hand, so they needed an opening to match.
• People's clothing was once so similar in style (not sure which era they're describing here) that the differences in buttons was the primary indicator of gender.
  
• The difference was due to some religious or moral reason, possibly to hide/show more skin depending on the viewer's perspective.
• Buttons in the back of a ladies' garment were easier to do/undo by oneself as well as a servant if placed a certain way.
  

The ideas keep coming. Like the chicken and the egg, no one really knows which came first. Or why.

Personally I'm still wondering - do you have a preference if you're buttoning up someone else's shirt? Or do you think the servant answer is simply a reason given to placate the curious?

References:
Photo: The Language of Clothes | Yahoo | Life's Little Mysteries | Fun Trivia | Snopes