Human Nature

, Volume 19, Issue 4, pp 389–413 | Cite as

Autism as the Low-Fitness Extreme of a Parentally Selected Fitness Indicator

  • Andrew ShanerEmail author
  • Geoffrey Miller
  • Jim Mintz


Siblings compete for parental care and feeding, while parents must allocate scarce resources to those offspring most likely to survive and reproduce. This could cause offspring to evolve traits that advertise health, and thereby attract parental resources. For example, experimental evidence suggests that bright orange filaments covering the heads of North American coot chicks may have evolved for this fitness-advertising purpose. Could any human mental disorders be the equivalent of dull filaments in coot chicks—low-fitness extremes of mental abilities that evolved as fitness indicators? One possibility is autism. Suppose that the ability of very young children to charm their parents evolved as a parentally selected fitness indicator. Young children would vary greatly in their ability to charm parents, that variation would correlate with underlying fitness, and autism could be the low-fitness extreme of this variation. This view explains many seemingly disparate facts about autism and leads to some surprising and testable predictions.


Autism Sexual selection Parental selection Sibling rivalry Fitness indicator 



For helpful feedback on these ideas and this manuscript, thanks to Rosalind Arden, Richard Harper, and Sydney Shaner.


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Copyright information

© United States Department of Veterans Affairs 2008

Authors and Affiliations

  1. 1.Department of Psychiatry and Mental Health (116A)Veterans Affairs Healthcare System and the University of California Los AngelesLos AngelesUSA
  2. 2.Department of PsychologyUniversity of New MexicoAlbuquerqueUSA
  3. 3.Departments of Psychiatry and Epidemiology/BiostatisticsUniversity of Texas Health Science Center San AntonioSan AntonioUSA

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