Passive acts, like listening to Mozart, will not make your child smarter. On the other hand, active engagement–learning to play an instrument or processing words–improves mental functioning. For instance, there is a positive relationship between the number of words a child hears every day and IQ scores.
Humans tend to hunker down in our own minds and trust what we already believe to be true. This emotion-based way of thought isn’t often the best way to think about anything, and often leads to gridlock.