Careening through this last year of Spike’s life – the days are long but the years fly by – I’ve seen the habits of my little ball of Y chromosomal commotion up close and personal. He is fast and fiercely playful, spirited and funny as hell. Nearing his second birthday, my wee hellion sits atop an imposing arsenal of cars, trucks and trains, things that go vroom, beep, chug, and choo. Alarmingly, that’s also the extent of his vocabulary. “Caw” is car, so his first sentence was naturally the keening and conjunction-challenged “caw caw caw.”

I have clearly if unconsciously bought into the research of the last 50 years like a well-trained seal. Much of it posits that gender differences are hardwired into children’s brains. Controlled studies demonstrate that boys and girls, when presented with a doll and a truck will gravitate to the object we associate with their sex. Ergo, Spike and things that go zoom.

But new thinking is challenging the status quo. Contemporary research now suggests that parents, educators, and community unconsciously amplify gender-specific behaviour, behaviour we believe is innate and ingrained. These assumptions then morph into self-fulfilling prophecies for children and, because of the brain’s plasticity, become part of the toddler’s anatomical reality. So the question of whether boys and girls learn differently is superseded by the relatively new notion that they are taught differently.

That and other issues are explored in Lise Eliot’s game-changing new book Pink Brain, Blue Brain: How Small Differences Grow Into Troublesome Gaps – and What We Can Do About It (Houghton Mifflin Harcourt). Eliot asserts that brains are not static densities; they are works in progress, shaped by experience. It’s the age-old nature vs. nurture potboiler but Eliot gooses the debate by staying away from the politics of gender and siding strictly with science.

She says that there are only two differences between girls’ brains and boys’ brains. The first is that a boy’s brain mass is larger. The second is that a girl’s brain matures more quickly than a boy’s. After that, something like a level playing field unfolds. Eliot doesn’t quibble with the fact that boys are more physical and girls more verbal. Her thesis is that brain-based differences can lessen with age if we challenge sex-based assumptions rather than feeding them. Instead of giving Sally a truck which she’s likely to reject, how about passing her a Lego set or a push toy to enhance her spatial dexterity, a skill typically associated with boys?

My sister was onto something when she and her husband began to raise their son. She had asked family members to buy him a tea set for his first birthday. After we played out our individual neurotic reactions to that tableau, I came away feeling it was a pretty nifty idea.

Recently, I asked her about it. She said “I didn’t see his gender so much at that point. I saw him as a little person, with all this potential. I thought he should have all sorts of different experiences growing up.” As a professional foodie, it was also important that her son be exposed to things related to his mom’s passion.

When biological determinism goes up against free-range, gender-neutral parenting, pre-fab scripts go out the window. I haven’t yet given Spike a doll and don’t know if I will. But he looks great in pink, red, and orange and we’ve yet to cut his long, honey-coloured hair, prompting many to remark on how pretty our little girl is.

In books, he’s far more chuffed about cars than colours and at the park more interested in slides and swings than a contemplative half hour creating shapes in the sandbox. In other words, my son is a boy, but also an individual. Eliot says the greater disparity is among a sex group, not between groups, and this, to me, is what raising a little person is all about. I want to challenge his fears, recognize his strengths, and help him tread the unknown, wherever they fit on the gender continuum.

It’s small comfort when people tell me not to worry about his lack of language, that he is, after all, a boy. Eliot says there’s a danger in relying on the idea that boys naturally speak later than girls and points to the fact that the earlier speech problems are addressed, the more effectively they’re resolved. Her concern about helping boys navigate the larger social milieu resonates deeply. “How can we help boys express their feelings, learn to read and write better, and feel at home in the classroom?”

This book filled me with great hope and optimism. Maybe my son will inherit a world where experience shapes character and where biology alone doesn’t determine a boy’s future.