A child psychologist investigated the effects of bilingualism on cognitive development. She assembled an equal number of 3, 4, 5, 6, and 7-year-old children. For each age level, half the kids were fluent in two languages, and half spoke only English. She showed each child a tower built from 5 Duplo blocks and explained that each block represented a family. She then gave the child Lego blocks and asked them to build a tower with the same number of families. Because Lego blocks are much smaller than Duplo blocks, a correctly built tower using 5 Lego blocks will be much shorter than the Duplo tower. However, young children, when given this task, tend to build a Lego tower that equals the height of the Duplo tower. She found that the bilingual children correctly built the Lego tower an average of two years earlier than the monolingual children; bilingual kids built a 5-block Lego tower at an average of 4 years of age while monolingual kids did so at an average of 6 years of age. The type of design is The type of design is Quasi-experiment simple design with 1 quasi independent variable Quasi-experiment factorial with 1 quasi independent variable and 1 true independent variable True-experiment factorial with 1 quasi independent variable and 1 true independent variable Quasi-experiment factorial with two quasi independent variables True experiment simple design with 1 true independent variable