Table 1.

Experimental materials.

Hierarchy of class concept	Materials
Superordinate level	animal, plant
Basic level	fruit, vegetable, bird, insect
Subordinate level	bird: swallow, magpie, sparrow, pigeon, oriole, kingfisher, tit, crow, wild geese, and lark
	insect: cockroach, ladybug, cricket, grasshopper, beetle, butterfly, bee, dragonfly, fly, and locust
	fruit: apple, orange, pear, peach, watermelon, banana, pineapple, tangerine, grape, and strawberry
	vegetable: cabbage, green vegetable, spinach, radish, cauliflower, eggplant, cucumber, lettuce, and celtuce