In this study, 100 infants were randomly assigned at birth to two groups of 50 infants each. Parents of infants in Group A were given a Mozart CD and instructed to play the CD in the presence of the infant at least once per week until the infant's first birthday. Parents of infants in Group B were to parent as usual, with no CD given. At the age of 8, all children were given an IQ test. Group A children scored significantly higher (n= 23,M= 107,SD= 13.7) on the IQ test than children from Group B (n= 18,M= 98,SD= 16.5). It is concluded that early exposure to Mozart increases intelligence in children.

With the abstract above in mind, what alternative explanations can you think of that might explain the difference in children's IQs?