title: Pseudoparadoxical impulsivity in restrictive anorexia nervosa: a consequence of the logic of scarcity.
abstract: OBJECTIVE
  To explain an apparently paradoxical pattern wherein sufferers of restrictive anorexia nervosa exhibit both rigorous self-restraint and episodic impulsivity.
  
  
  METHODS
  The experimental, historical, and clinical literatures were examined for evidence of psychological and behavioral changes accompanying severe dietary constriction; such changes were noted and compared with those reported to occur in anorexics.
  
  
  RESULTS
  Increased impulsivity in association with dietary constriction is described in diverse literatures. A number of lines of evidence suggest that the serotonergic system mediates this change.
  
  
  CONCLUSIONS
  Many forms of impulsivity can be understood as having once constituted fitness-enhancing responses to resource scarcity. It is suggested that an evolved psychological mechanism calibrates the individual's sensitivity to risk in light of future prospects. Self-injurious behaviors are explicable as misfirings of such a mechanism. Similarly, excessive exercising by anorexics may reflect the misdirection of reward systems that normally encourage adaptive increases in ranging behavior under conditions of scarcity.
authors.affiliation: Department of Anthropology, UCLA, Los Angeles, California 90095-1553, USA.
authors.forename: Daniel M T
authors.initials: DM
authors.lastname: Fessler
mesh_terms: D000818:Animals; D000856:Anorexia Nervosa / Q000523:psychology*; D005075:Biological Evolution; D004038:Diet, Reducing / Q000009:adverse effects / Q000523:psychology; D006801:Humans; D007175:Impulsive Behavior; D009765:Obesity / Q000503:physiopathology / Q000523:psychology; D012701:Serotonin / Q000097:blood; D013217:Starvation / Q000503:physiopathology* / Q000523:psychology*
chemical_list: D012701:Serotonin