ThePickards
standards, accessibility, and ranting and general stuff by the web chemist

BTP’s first day at school.

In the last week, we’ve seen his final day at nursery school, and he’s a little bit sad in some ways, because his nursery school isn’t anywhere near his proper school, so none of the other kids he knows will be going to his new school. He’s going to miss them, but on the bright side there are a few birthday parties in September/October so we’ll catch up with some of them then…

…and also he’s probably more excited about the idea of going to his new school, meeting his new teachers (again: they did home visits this week and came round briefly on friday), meeting his new classmates and also playing with the toy pirate ship that was in the classroom when they went to visit.

The GLW was really quite emotional dropping him off at his last day at nursery: our little baby isn’t so much of a baby anymore. He’s nearly five and he’s about to start school. Although I think she’ll struggle even more tomorrow — I imagine I will feel somewhat emotional about his first day at school, so I would imagine she will too…

School. My little baby. Going to school. In some respects, he just doesn’t seem big enough. Although technically, his head is huge.

I’m going to have to explain that last one, aren’t I?

Well, both BTP and SWP want bikes for their birthday. We’ve therefore been out today with Grandma (who is providing said bikes as her birthday present) to look at bikes and decide which ones the kiddies wanted. BTP has picked a Power Rangers bike — pitched for ages 4-6, and the perfect size for him as although he’s nearly 5, he’s probably slightly smaller than average — and SWP went for a Fireman Sam bike.

The only problem came with the helmets. Both Fireman Sam bikes and Power Rangers bikes have associated helmets, which you can buy for them. The only thing was that the respective helmets were too small for the kids. Not to worry, we thought, we’ll get BTP a helmet for a 6-8 year old, and SWP one for a 4-6 year old.

Still too small. Okaaay, we’ll try 8-10, and 6-8. Still too small. 10-12 and 8-10?

Nope.

The shop assistant, a little bemused, suggests that we’ll now need to try the ’small adult’ size. Only that’s still too small for our four year old and our two year old. Fortunately, the ‘medium adult’ is a perfect fit.

Medium adult?

These kids appear to me to have normal sized heads — I mean, they balance on tops of their necks, they don’t look like the Mekon or anything — so it is perhaps a tad surprising that they need a ‘Medium Adult’ cycle helmet.

So we decided to measure around the widest part of everyone’s skulls in order to see exactly how big they are…

• Mine is 58.5cm in circumference (23 in)
• The GLW’s is 57cm (22.4 in)
• BTP’s (almost 5) is 55cm (21.6 in)
• SWP’s (almost 3) is 54cm (21.3 in)

The average adult skull circumference is apparently in the range 54-57cm. Which obviously tells me that I have a big head (well, it needs to be, in order to fit my enormous intelligence, wit, and superhuman ego in), and that both my kids are comfortably past the 99th percentile in terms of skull circumference (although the charts I was looking at were US charts; there may be genetic differences with Northern Europeans although I wouldn’t have expected it…)

Alternatively it could potentially indicate that Grandma Jenny’s skull measurements were slightly inaccurate. But given that the reason for measuring them in the first place was that the kids needed medium adult helmets, and that ever since our kids have been small, we’ve regularly had to buy them hats for children in considerably older age groups, the measurements seem quite plausible.

(Note 1: at birth, child head size is normally around 80% of full adult size, and the vast majority of the growth occurs up to 3 years old — I would therefore expect that they would end up with ‘head sizes’ approximating to mine)

(Note 2: …it would be nice if I believed cranial capacity was an accurate reflection of intelligence, as this would therefore indicate that we are all dead clever but I’m not convinced that this is necessarily the case. It seems a little simplistic to generalise in this way; although evidence would seem to show that people with microencephaly where the size is 2 standard deviations below the mean do suffer significantly reduced ‘intelligence’, that is of course assuming that you are happy for it to be defined in this way.)

It would seem plausible then that we’ve all got very big heads. It would also seem plausible that while we have big heads, and we’re all at the upper end of the percentiles, the measurement has overestimated our head size slightly (e.g. by about 1cm each), putting us in at around the 99th percentile, rather than in the freakshow ‘look at those people with big heads’ section. Or maybe we do all just have huge heads and should charge people admittance to come and stare at us…

This entry was posted on Sunday, September 7th, 2008 at 11:25 pm and is filed under Life, Science, The Pickards. You can follow responses via my RSS 2.0 feed. You can leave a response or trackback from your site.