My dd is almost four. Her birthday is in February. The cutoff for birthdays around here is Dec. 1. She already knows her letters, the sounds that they make, how to write them. She knows the days of the week and the weather. She has friends around and we have a couple of playdates a week. The preschools I looked at wanted to put her into the threes group. She'd have been the oldest one there, and bored to tears as everything they do, she's been doing since she was two. They won't even test for readiness around here, which bugs me. She has also begged me not to send her. At all. She has been a shy child, but lately has come out of her shell a great deal. So I asked her recently if she wanted to go to school, and I received an emphatic NO. So, home she'll stay. If she's into school by the time she reaches Kindergarden, I'll send her to the multiage school in our district. If not, I will keep her home then, too. I am completely able to teach her what she needs at her own speed, in half the time. Oh, and did I mention, for free? The schools around here (the good ones, anyway...) want $120 per week. I just don't have that kind of money for hours away for socialization that number in the single digits. We go to the library, she takes swim lessons with a small group, she's in gymnastics and loves it. All with other authority figures, with kids her age and skill level. And I'm always where she can see me, which is her comfort level.
As for when people ask me about preschool, I have started to get a little annoyed. However, remember that this is the norm in the US. "Everybody" sends their kids to preschool, don't they?
I just educate them that we get all the socialization she needs in our community at large, and that she is academically ahead of her "class." I also mention that I am perfectly happy homeschooling her if that's what she needs. Ds, on the other hand, can't wait for school. He'll probably start in Kindergarden at the multiage school, and be deliriously happy, as he's a little social butterfly.
I really do think that practicing AP means following your child's lead in developmental and emotional issues. Sometimes they need a little nudge (the swim class was that nudge for us, but beneficial in many other ways as well...we spend hundreds of hours on the water in the summer, it's just plain safe for her to be comfortable in the water, plus she has asthma and swimming is great for her lung function), and sometimes we need them to run ahead a little bit!
It is really a personal issue for parents who are really aware of their children's needs and abilities...and if one has the money and their child really does benefit, as many do, from a few hours a week in preschool then the more power to them. However, there are so many parents right now in the US who just aren't AWARE of their children's needs and abilities...or they are very eager to have those four hours a week to themselves...or it's just that it is what "everyone" does, so that's what they do to! What gets me is that so many of THOSE parents think that they need to tell the rest of us how to parent.
Those are often the same parents, though, who ask me incredulously if ds (2+) is still nursing, when dc will sleep in their own bed, and whether I ever put my infants down ("that's one SPOILED baby!"). One has to take into consideration the nature and level of emotional education of most of the American Society and take those comments from such people with a grain of salt.