Response to vocal music in Angelman syndrome contrasts with Prader-Willi syndrome

Abstract

Parent-offspring conflict, or the conflict over resources between parents and their children due to differences in genetic relatedness, is the biological foundation for a variety of psychological phenomena, including sibling rivalry and child abuse. This form of conflict is particularly relevant to the domain of parental investment: the provisioning of resources to offspring by parents and alloparents. The kinship theory of genomic imprinting is the primary evolutionary explanation for the occurrence of specialized genetic expression in chromosomal domains relevant to phenotypic expression of parent-offspring conflict. Specifically, complementary parental contributions in the same region of the genome promote opposing parental demand behaviors. This theory predicts that people with genomic imprinting disorders will show alterations in traits and behaviors related to parental investment. In this paper, we apply this prediction to the psychological resource of parental attention, for which vocalizations in general, and music in particular, may be an honest signal. Individuals with Prader-Willi syndrome show increased physiological responses to music listening consistent with a reduced demand for parental investment. Here we report the complementary pattern necessary to support the theory: we find that individuals with Angelman syndrome demonstrate a relatively reduced physiological response to music, consistent with an increased demand for parental investment. In addition to presenting evidence of the value of applying the kinship theory of genomic imprinting to psychological phenomena, these data provide a comprehensive test of the theory that at least one aspect of human musical psychology evolved to mediate conflict over attentional demands between parents and offspring.