Why are white wines served in smaller wineglasses?

Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
Why are white wines served in smaller wineglasses?
—Manoj, Oman
Dear Manoj,
I’m one of those wine lovers that doesn’t have the desire (or cupboard space) for multiple sets of wineglasses. I prefer a set of all-purpose glasses. But you're right that there are a lot of grape- and region-specific wineglass shapes out there, and that wineglasses for reds tend to be larger. All those stemware shapes are designed to cater to each wine type, to best collect its aromas and allow it to "breathe," or benefit from exposure to oxygen, as needed. White wines are typically lower in both alcohol and tannins than red wines, so they don't need all that room to breathe that benefits some red wines so much.
—Dr. Vinny