Hi B.,
Okay-- fair warning. This will be long. I actually studied this quite a bit. So if you want a quick answer, just skip over mine!! If you want an in depth answer, but have dinner on the stove-- read this later, or dinner will burn. :)
There are two arguments to this one- and generally everyone has their bias, one way or the other. People who send their kids to preschool will almost always say that YOU should- and they'll assert all sorts of studies that say it helps the kids and that they do better in school. (People don't pay close enough attention to the studies-- if they looked at the demographics, they'd see that the studies showed that preschool only made a marked improvement with children who were developmentally delayed, or who were from poor and uneducated parents or from the inner city.)
Those who choose NOT to send their kids to preschool can site the studies and show that preschool doesn't result in significant improvement, (among kids who are developmentally on target) that it sometimes has negative behavioral effects, and that their kids do just as well if not better than kids who DID go to preschool.
So let's address this honestly- as both sides have their pros and cons.
Unless a parent has made no effort to educate their child at home (doesn't read to them, teach them colors, numbers, ABC's, give them opportunities to cut,paste, play matching games, etc) OR the child is behind for some other reason (major trauma that slowed things down, somekind of learning disability, etc) then the only REAL pro for preschool is that your child will learn all the "classroom politics" sorts of things a year ahead of those who wait until Kindergarten. Classroom politics being-- assigned seating, wait your turn, raise your hand, stand in a straight line, don't eat the paste :), etc. All things that they'll learn and adjust to in the in the very first week of Kindergarten- they don't need a year of preschool to learn it.)
Everything covered in preschool is supposed to prepare a child for Kindergarten. But you know what they learn in Kindergarten? The EXACT same things they learn in preschool, (or from mom at home) but just a little more. ANY Kindergarten teacher will tell you- and you check it yourself, that they spend the majority of the year teaching the ABC's, how to draw them and what sound they make, numbers, shapes, proper scissor use, and classroom behavior to prepare them for 1st grade. The "social" argument that people use is ridiculous UNLESS your child never plays with any other children and has never had to share a toy, take a turn, etc.
So really, the only pro to preschool is to get them used to the "school" environment. (Which for some kids may be a real benefit if they have a hard time with structured environments, rules, etc) Other than that-- depending on the preschool and it's schedule--(it's usually two or three times a week, for 2 or 3 hours) --preschool is a great time for kids to have organized and structured play and activities and to make some new friends-- and there's certainly nothing wrong with that! (AND it gives you a few deserved hours to yourself or at least a few hours with one LESS child-- which most parents REALLY appreciate but are too embarassed to say because they think it will make them sound like they just want to "get rid of the kid" for a few hours- but truly, there's nothing wrong with THAT either). But honestly, there really aren't any other benefits-- unless, as I said before, a child is behind academically, and doesn't know the ABC's, or has extrememly poor fine motor skills and lacks pre-writing or pre-reading skills, has poor social skills (doesn't share, etc) THEN preschool may be a great benefit.
Parents who don't send their kids to preschool are usually ones who are confidant that their child is already ready for school, and are teaching them (usually just through everyday play, reading, coloring, etc) at home. And they'll also tell you that their kids did just fine in Kindergarten, if not better than most of the other kids. I had this experience myself. My children did not go to preschool and they were all and still are the top students in all their classes- 6th, 4th and 1st grades, now. And according to my sister in law-- who taught Kindergarten, and is now doing 3rd grade, she had the same experience. Each year, her best students were the ones that never went to daycare or preschool- and even SHE was surprised. She'd assumed that her best students would be the ones that were supposedly "prepared" by preschool and daycare environments, but each year, found the opposite to be true.
Now that's not to suggest that preschool was somehow BAD for those kids-- maybe individually, they WERE better prepared for Kindergarten and wouldn't have done as well as they did had they NOT gone to preschool-- my sister-in-law just noted that
the kids who hadn't gone to preschool were always her best students. (Which personally, I believe simply signifies that one on one preparation by a parent is better than 10 or 20 to one in a preschool)
Now again-- you don't have to take my word for all this-- I'd suggest you talk to the Kindergarten teachers at your local school. It's not uncommon at all for the kids who stayed at home until Kindergarten, to be the ones most prepared, most socially mature and the best behaved. And again, most Kindergarten teachers will tell you, and you can ask them yourself to verify this-- that even when kids who DIDN'T go to preschool come in and ARE a little behind, they catch up very quickly and perform equal to or higher than the kids who went to preschool. If your school district has an early childhood center that uses the Parents as Teachers program, they can give you some great info, too. They're a wonderful source!
You have to realize that Kindergarten didn't use to be compulsory. Kindergarten USED to be what preschool is NOW. Kindergarten was what people USED to send they're kids to, to prepare them for school. Back in the 60's and before, elementary school used to start with 1st grade. Now- everyone thinks they have to send they're kids to preschool, to prepare them for Kindergarten. And to further that, many states are considering legislation to make PRESCHOOL compulsory too. So then what will happen? There will places to send your child to prepare them for PRESCHOOL.
If you feel like your child is on target for her age and doesn't really need preschool-- then go with that. On the other hand, even if she IS ready, and you just want her to have a few days a week where she can go and have fun, organized/educational activities with other kids (and maybe give you a couple needed and well-deserved hours to yourself!) then that's fine too. I just don't want you to fall for the "oh you HAVE to send her -- she'll do better in school! She'll fall behind if you don't!" garbage. Preschool has no REAL or meaningful advantage unless your child is somehow behind.
If you're already doing educational things with her at home, and she's doing similar things with her friends from the neighborhood, and you're taking her to the library for reading/activity time-- then you've already got the "organized/educational activity" thing covered and she'll probably soar through school.
The main thing is- don't feel pressured one way or the other. You know your child, do what you think is best for her, and don't let anyone make you feel like you're doing her a disservice by NOT sending her, or sending her. Just know that if she's already on target, that it isn't going to put her ahead of anyone or "prepare" her for Kindergarten, and it isn't going to hurt her to go, either.
Best wishes!
T.