Person: Krasnow, Max
Loading...
Email Address
AA Acceptance Date
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Krasnow
First Name
Max
Name
Krasnow, Max
6 results
Search Results
Now showing 1 - 6 of 6
Publication Response to vocal music in Angelman syndrome contrasts with Prader-Willi syndrome(Center for Open Science, 2018-08-13) Kotler, Jennifer; Mehr, Samuel; Egner, Alena; Haig, David; Krasnow, MaxParent-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.Publication Meeting now suggests we will meet again: Implications for debates on the evolution of cooperation(Springer Nature, 2013) Krasnow, Max; Delton, Andrew W.; Tooby, John; Cosmides, LedaHumans are often generous, even towards strangers encountered by chance and even in the absence of any explicit information suggesting they will meet again. Because game theoretic analyses typically conclude that a psychology designed for direct reciprocity should defect in such situations, many have concluded that alternative explanations for human generosity— explanations beyond direct reciprocity—are necessary. However, human cooperation evolved within a material and informational ecology: Simply adding consideration of one minimal ecological relationship to the analysis of reciprocity brings theory and observation closer together, indicating that ecology-free analyses of cooperation can be fragile. Using simulations, we show that the autocorrelation of an individual’s location over time means that even a chance encounter with an individual predicts an increased probability of a future encounter with that same individual. We discuss how a psychology designed for such an ecology may be expected to often cooperate even in apparently one-shot situations.Publication Group Cooperation without Group Selection: Modest Punishment Can Recruit Much Cooperation(Public Library of Science, 2015) Krasnow, Max; Delton, Andrew W.; Cosmides, Leda; Tooby, JohnHumans everywhere cooperate in groups to achieve benefits not attainable by individuals. Individual effort is often not automatically tied to a proportionate share of group benefits. This decoupling allows for free-riding, a strategy that (absent countermeasures) outcompetes cooperation. Empirically and formally, punishment potentially solves the evolutionary puzzle of group cooperation. Nevertheless, standard analyses appear to show that punishment alone is insufficient, because second-order free riders (those who cooperate but do not punish) can be shown to outcompete punishers. Consequently, many have concluded that other processes, such as cultural or genetic group selection, are required. Here, we present a series of agent-based simulations that show that group cooperation sustained by punishment easily evolves by individual selection when you introduce into standard models more biologically plausible assumptions about the social ecology and psychology of ancestral humans. We relax three unrealistic assumptions of past models. First, past models assume all punishers must punish every act of free riding in their group. We instead allow punishment to be probabilistic, meaning punishers can evolve to only punish some free riders some of the time. This drastically lowers the cost of punishment as group size increases. Second, most models unrealistically do not allow punishment to recruit labor; punishment merely reduces the punished agent’s fitness. We instead realistically allow punished free riders to cooperate in the future to avoid punishment. Third, past models usually restrict agents to interact in a single group their entire lives. We instead introduce realistic social ecologies in which agents participate in multiple, partially overlapping groups. Because of this, punitive tendencies are more expressed and therefore more exposed to natural selection. These three moves toward greater model realism reveal that punishment and cooperation easily evolve by direct selection—even in sizeable groups.Publication Are Humans Too Generous and Too Punitive? Using Psychological Principles to Further Debates about Human Social Evolution(Frontiers Media S.A., 2016) Krasnow, Max; Delton, Andrew W.Are humans too generous and too punitive? Many researchers have concluded that classic theories of social evolution (e.g., direct reciprocity, reputation) are not sufficient to explain human cooperation; instead, group selection theories are needed. We think such a move is premature. The leap to these models has been made by moving directly from thinking about selection pressures to predicting patterns of behavior and ignoring the intervening layer of evolved psychology that must mediate this connection. In real world environments, information processing is a non-trivial problem and details of the ecology can dramatically constrain potential solutions, often enabling particular heuristics to be efficient and effective. We argue that making the intervening layer of psychology explicit resolves decades-old mysteries in the evolution of cooperation and punishment.Publication Genomic Imprinting Is Implicated in the Psychology of Music(Center for Open Science, 2017-01-27) Mehr, Samuel; Kotler, Jennifer; Howard, Rhea; Haig, David; Krasnow, MaxWhy do people sing to babies? Human infants are relatively altricial and need their parents’ attention to survive. Infant-directed song may constitute a signal of that attention. In Prader-Willi syndrome (PWS), a rare disorder of genomic imprinting, genes from chromosome 15q11–q13 that are typically paternally expressed are unexpressed, which results in exaggeration of traits that reduce offspring’s investment demands on the mother. PWS may thus be associated with a distinctive musical phenotype. We report unusual responses to music in people with PWS. Subjects with PWS (N = 39) moved more during music listening, exhibited greater reductions in heart rate in response to music listening, and displayed a specific deficit in pitch-discrimination ability relative to typically developing adults and children (N = 589). Paternally expressed genes from 15q11–q13, which are unexpressed in PWS, may thus increase demands for music and enhance perceptual sensitivity to music. These results implicate genomic imprinting in the psychology of music, informing theories of music’s evolutionary history.Publication Parent-Offspring Conflict and the Evolution of Infant-Directed Song(Elsevier BV, 2017-09) Mehr, Samuel; Krasnow, MaxWe present a theory of the origin and evolution of infant-directed song, a form of music found in many cultures. After examining the ancestral ecology of parent-infant relations, we propose that infant-directed song arose in an evolutionary arms race between parents and infants, stemming from the dynamics of parent-offspring conflict. We describe testable predictions that follow from this theory, consider some existing evidence for them, and entertain the possibility that infant-directed song could form the basis for the development of other, more complex forms of music.