Leave no slice behind. Not eating the last piece of pie would have hugely insulted your friends in 1905.
According to etiquette books of the past, it was pretty easy to be offensive. To show you were of good breeding, you had to adhere to strict parameters surrounding speech, behavior, dress, and eating. Some of those mores were so detailed and odd that they are absolutely foreign to us now. At any rate, by the standards of 100 years ago, you are an incredibly rude person.
1. At the Table
Today, most women at a baby shower will leave the last piece of scrumptious chocolate cream pie to wilt on the plate, instead of being the selfish soul to "take the last piece." (It has been my experience that neither men nor children suffer from this crippling politeness.) According to Dr. Jefferis, however, writer of 1904's Search Lights on Health, it is rude not to take the last piece. "Do not hesitate to take the last piece on the dish, simply because it is the last. To do so is to directly express the fear that you would exhaust the supply."
He provides further instruction on good table manners. For instance, should you find a worm or insect in your food, say nothing of it. In fact, no unpleasant talk at all. No matter what. "If an accident of any kind so ever should occur during dinner, the cause being who or what it may, you should not seem to note it… Should you be so unfortunate as to overturn or to break anything, you should make no apology. You might let your regret appear in your face, but it would not be proper to put it in words." The gravy boat is spilled. Anoint your head in ashes, gnash your teeth, and rend your clothing. Just be quiet about it or you'll make things awkward.
2. In Language
Mrs. Duffey, a 19th century expert on manners and feminist author of the 1877 The Ladies' and Gentlemen's Etiquette, warns her readers to be careful in conversation. Don't ask impertinent questions. Which could be any question, since you have no idea what will offend your companion. Better to avoid the problem altogether and never allow the lilt of a question mark to stain your speech. If you want to know how your friend's brother is, do not say, "How is your brother?" Say, "I hope your brother is well." Passive-aggressive nosiness is far more acceptable than brazen, well-intentioned curiosity.
Jefferis goes further, offering a list of language that is too ignorant to be used in polite company.
"Don't say feller, winder, to-morrer, for fellow, window, tomorrow." Here Jefferis clearly underestimates the charm of someone who talks like Granny Clampett.
And his crowning piece of grammatical advice, "Don't say I say, says I, but simply say I said." (Direct quote, hand to God.)
Some of his advice is still appropriate.
"Do not always commence a conversation by allusion to the weather." Or asking about the kids. (They're kids. They run around being useless, sticky, and just cute enough so that you'd feel bad if you didn't feed them.) Or asking about the other person's work, which you know you're not really interested in. Besides, you're not supposed to be asking questions anyway.
By process of elimination, the best way to initiate conversation would be by declaring something impersonal, interesting, and educated. Greet a new person, shake hands, and declare, "I am fond of potatoes, which the French call 'apples of the earth'." See where that takes you.
3. On the Street
Men and women are expected to conduct themselves differently while walking down the street. Men are not to lurk in doorways.
"A gentleman will not stand on the street corners or in hotel doorways, or store windows and gaze impertinently at ladies as they pass by. This is the exclusive business of loafers," says Jefferis.
Whereas it is a man's job to make himself visible, a woman is asked to do the opposite. "Your conduct on the street should always be modest and dignified. Ladies should carefully avoid all loud and boisterous conversation or laughter, and all undue liveliness in public." To appear at all happy or talkative would draw the attention of those impertinent loafers. Also, be ever so careful how much ankle those creepers can get off you:
"In crossing the street a lady should gracefully raise her dress a little above her ankle with one hand. To raise the dress with both hands is vulgar, except in places where the mud is very deep."
As for offering to carry a lady's packages, according to Emily Post, writing in the 1922 print of Etiquette in Society, in Business, in Politics and at Home, a real lady wouldn't be carrying "bundles" in the first place. Asking a man to do so is to emasculate him in front of the entire town. An exception is allowed for small, tidy square packages or anything that is obviously nice, like flowers or fruit. Otherwise, should the woman ask for help, "[She should not] wonder why her admirer never comes to see her anymore!" It's an indisputable scientific fact that asking a man to carry shopping left more women alone to die old maids than did the casualties of the First and Second World Wars combined.
4. Specifically for Ladies
There are two things a lady needs to know to survive in polite company. How to sit, and how to please men. I know, that sounds medieval and ridiculous, but if a lady doesn't sit properly how will you know she's a lady?
How to sit
Emily Post reminded women how their mothers were not allowed to cross their knees, put hands on their hips, twist in a chair, or lean back. But by the '20s, these things were allowed, within reason.
No lady should cross her knees so that her skirts go up to or above them; neither should her foot be thrust out so that her toes are at knee level. An arm a-kimbo is not a graceful attitude, nor is a twisted spine! Everyone, of course, leans against a chair back… but a lady should never throw herself almost at full length in a reclining chair or on a wide sofa when she is out in public.
The proper way for a lady to sit is in the center of her chair, or slightly sideways in the corner of a sofa. She may lean back, her hands relaxed in her lap, her knees together, or if crossed, her foot must not be thrust forward so as to leave a space between the heel and her other ankle. On informal occasions she can lean back in an easy chair with her hands on the arms.
To clarify, you may use the chair's armrests. On informal occasions only. Preferably in a locked room, alone.
How to please a man
One can always trust Dr. Jefferis to be plainspoken in even the most ticklish of subjects.
No woman can afford to treat men rudely. She must remember that the art of pleasing and entertaining gentlemen is infinitely more ornamental than laces, ribbons, or diamonds…. and as women are more or less dependent upon man's good-will, either for gain or pleasure, it surely stands to their interest to be reasonably pleasant and courteous in his presence or society.
This sentiment, that women are dependent on man's good nature like a dog upon its master's, may sting and enrage. But considering the time it was written, what is even more stinging is the possible truth of it.
So you need to be careful exactly how you set about pleasing your man. For women are like books. No, wait. They're like seed corn. No! Better! Ornamental furniture!
For women are like books — too much gilding makes men suspicious, that the binding is the most important part. The body is the shell of the soul, and the dress is the husk of the body; but the husk generally tells what the kernel is. As a fashionably dressed young lady passed some gentlemen, one of them raised his hat, whereupon another, struck by the fine appearance of the lady, made some inquiries concerning her, and was answered thus: "She makes a pretty ornament in her father's house, but otherwise is of no use."
5. Gallantry for Gentlemen
As is often the case in old advice manuals, instruction for men on how to better themselves is scant. The little bit that Jefferis offers is especially charming for how applicable it still is today.
Propriety is outraged when a man of sixty dresses like youth of sixteen. It is bad manners for a gentleman to use perfumes to a noticeable extent. Avoid affecting singularity in dress. Expensive clothes are no sign of a gentleman.
Friend, you're 46. Put away the board shorts. Take off the baseball cap or at least put it on straight. Leave off the Axe body spray. And if you paid $200 for a pair of jeans that already have strategic holes ripped into them, well, there is nothing any advice book can do for you.
One of the only other tricky elements a man must navigate is when it is appropriate to give a lady his arm. It is a sexually potent act that leads many a fine girl to ruin. Arm-offering is how our streets came to echo with the plaintive cries of unwed mothers and their starving ill-gotten young.
Now, a gentleman may offer his arm to an old lady at any time. To a young woman who is not his wife, there are very specific rules. It must be dark and treacherous to warrant touching, say crossing a busy, icy road at night. He may offer his arm if he is the usher at a wedding, but not if he is escorting a woman at a ball, as that is no longer the fashion. A gentleman never takes a lady's arm, as that would make him a sissy boy.
It was refreshing to encounter one last piece of advice from Mrs. Duffey, who politely shows her feminist colors regarding how a gentleman should treat a lady.
If you are a gentleman, never lower the intellectual standard of your conversation in addressing ladies. Pay them the compliment of seeming to consider them capable of an equal understanding with gentlemen. You will, no doubt, be somewhat surprised to find in how many cases the supposition will be grounded on fact, and in the few instances where it is not. When you "come down' to commonplace or small talk with an intelligent lady, one of two things is the consequence: She either recognizes the condescension and despises you, or else she accepts it as the highest intellectual effort of which you are capable, and rates you accordingly.