Recently there have been conscious efforts to include stories in curriculum…

Gender-sensitive curriculum design works on a simple principle: children absorb ideas about "appropriate" male and female roles from the stories, images, and activities they repeatedly see in textbooks. When a curriculum keeps assigning men to outdoor, adventurous, or authority-linked roles and women to indoor, caregiving roles, it reinforces gender stereotyping — the belief that certain roles or traits belong fixedly to one gender. Deliberately reversing these role assignments in curricular material is a recognised strategy used to counter that reinforcement.

In this item, the story assigns household work to the father and adventure activities to the mother — the reverse of the usual pattern. Repeated exposure to such counter-stereotypical portrayals loosens the fixed association between gender and role, which is exactly the mechanism by which curriculum content works to eliminate gender stereotyping among learners.

Checking the alternative explanations against their own claims:

• Strengthening bias means asserting that one gender's abilities or worth are lesser than the other's; varying which parent performs which activity in one story does not, by itself, assert such an inequality — it changes who is shown doing what, not whose worth is judged higher.

• Gender constancy, from Kohlberg's stage theory of gender development, is a child's own understanding that their gender stays the same over time regardless of activity or appearance — a fact about a child's self-concept, not about how textbook roles are assigned to adults.

• Gender discrimination means unequal treatment or opportunity on the basis of gender; reassigning which parent does which activity in one story does not by itself restrict opportunity or treatment for any group.

So the curriculum change is best explained as a conscious effort to eliminate gender stereotyping by presenting roles that break the conventional mould.