Don’t ‘boy mum’ me. These stereotypes around raising children do enormous harm | Rhiannon Lucy Cosslett

Biology can play a role in how girls and boys behave. But it's parents who turn small differences into big ones

According to the internet, I'm a boy mum". It's not a term I'd heard until I gave birth to a baby boy. Suddenly, I was being bombarded with videos about the nightmare in store for me. This was footage showing the kind of destructive male-toddler behaviour that Jackass stars Johnny Knoxville and Bam Margera would deem too risky. Meanwhile, their mothers were portrayed as longsuffering, harried, hard-as-nails veterans of the boy-toddler insane asylum.

My son is very physically active, but he's also a gentle, cautious child, so this doesn't resonate with me, or with several of the boy mums" I know. (Meanwhile, some of the girl mums" spend their days chasing their Tasmanian Devil-esque daughters like they're in a Looney Tunes cartoon.) Yet it's everywhere. Then, last week, I saw a report that found girls were playing outside less than boys, even at two years old - something that shocked the researchers, who hadn't expected to see socialised gender roles emerging so early.

Rhiannon Lucy Cosslett is a Guardian columnist