Answer:
The answer is gender schema.
Step-by-step explanation:
A schema can be described as a "block of information" about a certain concept. For example, your schemas about a horse might include: four legs, long face, tall and heavy... so you will recognise a horse based on these and other characteristics. Schemas can be modified (even added or substracted) in order to learn new concepts.
This way, gender schemas are a set of characteristics, especially as observed by children, about what is common in males or females. In the example, Garth's schemas of a girl likely do not include playing with trucks, but playing with dolls or toy kitchens. As he grows up, he might change his gender schemas and realise that girls can also enjoy playing traditionally "boyish" games.