What an awesome thesis topic.
The short version of the (also short) article at the link is that the author, a woman who just graduated from Occidental College, wrote her senior thesis about how women eat differently in front of other women vs. in front of men. She observed 76 pairs of diners at two high-end West Coast restaurants and discovered that when they're with men, women are, basically, daintier.
In the comments, there's some back and forth about why that is and about how things might be different in more casual settings, which is an interesting observation. And of course, because of who I am, before fully believing anything, I'd want to know a lot more backstory.
But still - what a topic! I love it! Especially since I spend so much time watching other people eat at restaurants, as I eavesdrop on their awkward first dates and breakup conversations while I try to figure out if we made good ordering choices and whether the wait staff is equally well-trained.
I can't believe I've never thought about doing an etiquette ethnography related to this stuff. It just might happen.