Evolutionary Medicine (continued)

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Briana Horton
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1 Evolutionary Medicine (continued) Behavioral immune system: Evolved psychology to detect and avoid pathogen threats disgust group bias (ethnocentrism and xenophobia) Mental Disorders schizophrenia psychopathy depression

The behavioral immune system: Disgust disgust: expression in infants associated with bitter taste generalized later: unclean, inedible, possibly infectious things e.

2 The behavioral immune system: Disgust disgust: expression in infants associated with bitter taste generalized later: unclean, inedible, possibly infectious things e.g: feces, rotten food, bodily secretions, signs of illness reduced by exposure, culturally modifiable disgust face: clenched nostrils, squinty eyes, pursed lips: decreases sensory exposure?

3 The behavioral immune system: disgust and immunity Exposure to pictures of guns or disease increased immune marker in white blood cells (not to threatening stimuli in general). From Schaller et al. 2010

4 The behavioral immune system: social bias Does avoiding outsiders reduces exposure to novel pathogens? people who felt vulnerable to disease (q aire) more xenophobic what if you prime people to think about disease? Endorsement Nigerian Immigrants Scottish Immigrants Accidents Diseases Percent Allocation of Funds Foreign Immigrants Familiar Immigrants Accidents Diseases Salient Threat Salient Threat Figure2. Interaction between disease salience and geographical origin of immigrantson endorsement of potential immigration (Study5). Figure3. Interaction between disease salience and foreign-nessof geographical areason allocation of immigration advertising budget (Study6). from Faulkner et al.

5 The behavioral immune system: social bias does sensitivity to disease lead to in-group bias? (Maybe) people who feel vulnerable to disease: more in-group bias pregnant women in first trimester? more sensitive to disgust Fig. 1. Intergroup bias and nausea over thecourse of pregnancy. Thesolid line depicts the relative attraction for the American over the foreign target across week of pregnancy. The dashed line depicts self-reported nausea. more in-group bias from Navarrete et al 2007

6 How do we understand mental health problems? polygenic traits (extremes of normal variation) trade-offs (schizophrenia?) defenses-adaptations (psychopathy?) novel environments (depression?) smoke-detector theory (phobias? PTSD?)

7 Polygenic Traits Some mental health susceptibility may be: extremes of adaptive emotional responses extremes of adaptive personality variation fear phobia selfishness, egotism psychopathy sadness depression

8 Schizophrenia: A trade-off? Schizophrenia is heritable (Crespi et al: under selection). How is it maintained in the population? Schizotypy: a personality type, vulnerable to schizophrenia Are creative people prone to schizotypy? Nettle 2006: compared poets, artists, mathematicians, controls and schizophrenia patients on schizotypy questionnaire Were creatives similar to schizophrenia patients?

9 D. Nettle, Journal of Research in Personality 2006 Schizotypy and Creativity? unusual experiences: hallucinatory & magical thinking, perceptual disortions scores for poets and artists as high as for schizophrenia patients

10 Schizotypy and Creativity? Caveats: low scores for mathematicians (also creative) scores for poets and artists not correlated with negative symptoms

11 Psychopathy glib and superficial charm inflated ability of self-worth lack of remorse or guilt manipulative and deceitful persistent lying impulsive, irresponsible seeks stimulation promiscuity (among others) from the Hare Psychopathy Checklist-Revised

12 Psychopathy Psychopathy (factors): callous affect interpersonal manipulation erratic lifestyle criminal tendencies from the Self-Report Psychopathy scale, Paulhus et al.

13 Psychopathy: An adaptation? An extreme end of a personality trait (like schizotypy) Is it adaptive? If so what for? EP hypothesis: social deception, cheating How is it maintained in the population? EP Hypotheses suggest primary psychopathy favored when: rare (frequency-dependent selection) can escape sanctions (mobility, anonymity)

14 Sub-clinical psychopathy as strategic manipulation Gervais et al: Is it strategic? Prediction: primary (manipulative, callous) psychopaths will defect on people who are not valuable to them. value in quality of partner value in likelihood of future interactions

15 Psychopathy and strategic manipulation Gervais et al., Proc. Royal Soc. B. 2013

16 Psychopathy and strategic manipulation

17 Psychopathy and strategic manipulation

18 Sadness and Depression Is sadness adaptive? Hypotheses: caused when can t achieve goals: stop, change course signals submission, decrease likelihood of attack Depression correlated with economic development (mismatch?) Nesse: human social life today leads to many people being trapped pursuing unreachable goals.

19 Summary The behavioral immune system disgust: elicited by things that might make you sick sensitivity to disease may enhance group bias Mental Health Many mental ills may be extremes of normal traits Trade-offs: Schizophrenia and creativity? Adaptations: Psychopathy and machiavellianism? Mismatch: Sadness and depression

LEADERSHIP A WALK ON THE DARK SIDE

LEADERSHIP A WALK ON THE DARK SIDE JOHN SHIELDS PROFESSOR OF HRM & ORGANISATIONAL STUDIES THE UNIVERSITY OF SYDNEY BUSINESS SCHOOL john.shields@sydney.edu.au 1. The Good Leader Outline 2. The Dark-side