Here’s a couple of books that might be interesting to you:
www.amazon.co.uk/Invisible-Women-Exposing-World-Designed/dp/1784706280/ref=asc_df_1784706280/
www.waterstones.com/book/testosterone/carole-hooven/rachel-perry/9781788402934
obviously the sex differences between boys and girls become more pronounced at puberty (both physically and behaviourally) but we use different growth charts for height and weight from birth (and I have been told by a midwife friend that there are differences in pregnancy too) and if physical differences exist from birth (or prior to birth) it would be weird to assume that behaviourally differences only exist later on - they are generally noticeable once you get the kids into a more or less M/F 50/50 group of 20 or more, eg infant school!)
For the record, I was one of those Duracell bunny girls myself, we definitely exist and are not erased by the acknowledgment of different averages. I have a massive soft spot for the energetic, full-on kids of either sex (and especially the girls due to personal bias ❤️)
There are always naturally occurring outliers and there is absolutely nothing wrong with any of us who don’t fit in with the expected ‘norms’.
Obviously our individual genes play a massive role too.
(the next bit is just an expansion on my thoughts, it’s absolutely not said in relevance to the personal stories on this thread, I am just a rando on the internet and I absolutely do not want to make anyone worried or upset! It’s purely general conversation)
Calculating average behaviours in childhood is additionally complicated by things like physical disability, SEN, traumatic birth, gestational age at birth etc (which is why an older kid/teenager referred to CAMHS will have their full medical history taken, including mum’s health in pregnancy and pre pregnancy).
Boys are more likely to be diagnosed with ASD/ADHD (especially at primary school age) but the actual occurrence of such neurodifferences might be a lot more equal than the diagnostic figures suggest (but that’s partly because of sex differences in average presentations, with girls less likely to be ADHD and more likely to be ADD and girls being better at ‘masking’ ASD, especially in the prepubertal years).