Despite the widespread belief in the cognitive benefits of music lessons, only five published randomized controlled trials have tested this claim. The findings are far from conclusive. Just one showed an unequivocally positive, though small, effect of piano or voice lessons on children’s IQs — but two subsequent trials failed to replicate this effect. Another trial found a positive effect of classroom music on kindergartners’ spatial reasoning — but not on four other tests. Another trial found increases in general cognitive skills, but not academic achievement, after two years of piano lessons — but not after one or three years.

In a paper published this month in the journal PLoS One, my colleagues Adena Schachner, Rachel Katz, Elizabeth Spelke and I report the results of two new randomized controlled trials that we conducted at Harvard’s Laboratory for Developmental Studies. We studied the effects of a popular type of early childhood music enrichment class, in which parents and children sing songs and lullabies, play instruments and musical games and listen actively to recorded music. Instead of IQ tests, which measure general intelligence, we used more sensitive tests of specific cognitive domains: spatial, linguistic and mathematical skills.

In the first trial, we randomly assigned 29 preschoolers to six weeks of music or visual arts classes. When we tested them afterward, we found no group differences in performance on linguistic or mathematical tests and only modest differences on two spatial tests. Seeking to replicate the result, we ran a second trial with 45 preschoolers, randomly assigning them to either the same music classes or to no classes. This time we found no group differences whatsoever, and in the combined cohort of 74, the results were negative. Overall, we found no evidence that a brief series of parent-child music classes improved preschoolers’ cognitive skills.

You might be tempted to conclude that our studies debunk the claim that music makes you smarter. That conclusion is false. Our studies cannot rule out the existence of cognitive benefits of music lessons. Before anyone can justify a strong conclusion about the existence or nonexistence of such benefits, many more randomized controlled trials must be conducted.

But even if future studies fail to support the existence of music’s cognitive benefits, this should not deter parents from providing their children with music lessons. Our findings in no way diminish the intrinsic value of music education, which is so obvious that it needs no validation from empirical study. We’ve made literature, history, mathematics and science core elements of education. Why should music — a human activity older than the written word — be any different?