You can certainly start by complimenting a girl's appearance (tends to improve the mood of a girl of any age)
From Lord Chesterfield, writing in 1747 (i.e. this advice is older than America), emphasis mine:
Women have, in general, but one object, which is their beauty; upon which, scarce any flattery is too gross for them to swallow. Nature has hardly formed a woman ugly enough to be insensible to flattery upon her person; if her face is so shocking, that she must in some degree, be conscious of it, her figure and her air, she trusts, make ample amends for it. If her figure is deformed, her face, she thinks, counterbalances it. If they are both bad, she comforts herself that she has graces; a certain manner; a 'je ne sais quoi,' still more engaging than beauty. This truth is evident, from the studied and elaborate dress of the ugliest women in the world. An undoubted, uncontested, conscious beauty, is of all women, the least sensible of flattery upon that head; she knows that it is her due, and is therefore obliged to nobody for giving it her. She must be flattered upon her understanding; which, though she may possibly not doubt of herself, yet she suspects that men may distrust.
I once heard that Casanova once said that his secret to seducing women was to compliment the beautiful on their intelligence and the intelligent on their beauty.
Note: This is based on anecdotal evidence, personal experience (I have worked with children for many years. It is my full-time job.) and "general knowledge" rather than scientific studies, though I welcome any relevant links on either side of the issue.
The holidays are upon us, and I would guess that even though most of us are atheists, that we will still be spending time with our extended families sometime in the next week. These extended families are likely to include nieces and nephews, or other children, that you will have to interact with (probably whether you like it or not...)
Many LW-ers might not spend a lot of time with children in their day-to-day lives, and therefore I would like to make a quick comment on how to interact with them in a way that is conducive to their development. After all, if we want to live in a rationalist world tomorrow, one of the best ways to get there is by raising children who can become rationalist adults.
PLEASE READ THIS LINK if there are any little girls you will be seeing this holiday season:
How To Talk to Little Girls: http://www.huffingtonpost.com/lisa-bloom/how-to-talk-to-little-gir_b_882510.html?ref=fb&src=sp&comm_ref=false
I know it's hard, but DON'T tell little girls that they look cute, and DON'T comment on their adorable little outfits, or their pony-tailed hair. The world is already screaming at them that the primary thing other people notice and care about for them is their looks. Ask them about their opinions, or their hobbies. Point them toward growing into a well-rounded adult with a mind of her own.
This does not just apply to little girls and their looks, but can be extrapolated to SO many other circumstances. For example, when children (of either gender) are succeeding in something, whether it is school-work, or a drawing, DON'T comment on how smart or skilled they are. Instead, say something like: "Wow, that was a really difficult math problem you just solved. You must have studied really hard to understand it!" Have your comments focus on complementing their hard work, and their determination.
By commenting on children's innate abilities, you are setting them up to believe that if they are good at something, it is solely based on talent. Conversely, by commenting on the amount of work or effort that went into their progress, you are setting them up to believe that they need to put effort into things, in order to succeed at them.
This may not seem like a big deal, but I have worked in childcare for many years, and have learned how elastic children's brains are. You can get them to believe almost anything, or have any opinion, JUST by telling them they have that opinion. Tell a kid they like helping you cook often enough, and they will quickly think that they like helping you cook.
For a specific example, I made my first charge like my favorite of the little-kid shows by saying: "Ooo! Kim Possible is on! You love this show!" She soon internalized it, and it became one of her favorites. There is of course a limit to this. No amount of saying "That show is boring", and "You don't like that show" could convince her that Wonderpets was NOT super-awesome.