Until recently, I thought my own modest achievements were due to my parents’ values, without considering what was happening socially at the time. My mother and I both had caring, aspirational, working-class parents - but she polished needles in Singer’s factory while I became a teacher. My environment differed significantly from hers, and that had little to do with parenting.

In her book The Nurture Assumption, Judith Rich Harris challenges the belief that parents are the most important factor in child development. She rejects the nature versus nurture debate, on the grounds that “nurture” implies rearing, a task we normally associate with parents. She replaces “nurture” with “environment” and demolishes many notions about the extent to which parents influence their children, placing more emphasis on the peer group.

In teacher training, I was taught the peer group became important at around age 9. However, I watched a two-year-old being scolded by his mother for climbing on to a stool to reach for a biscuit, and finding that imitating adults brings little reward, since his mother moved the biscuits out of sight. At playgroup, he would run noisily up and down the room. This was frowned upon by the play leaders, but well rewarded by the other boys. Being accepted in a gang is already a strong pull for a toddler.

The notion that bad behaviour might not all be the parents’ fault is uncomfortable for those imbued with the staffroom mantra of “I blame the parents”. It is also uncomfortable for those who have promoted teaching parenting skills as the answer.

Our model needs to develop, if only because blaming the parents and seeking to educate them has got us precisely nowhere.

Jeannie Mackenzie, Gateside Place, Kilbarchan, Johnstone.