Introduction to Biological Preparedness and Conditioned Fears

• Concept of Prepared Fears

  • The term "prepared fears" was introduced by Susan Mineka (1992) and refers to the notion of "evolutionary memories"—emotional legacies resulting from natural selection.

• Research by Mineka and Cook (1993):

  • Conducted an experiment with lab-reared rhesus monkeys who had no prior exposure to snakes.
  • They presented these monkeys with a videotape showing other monkeys reacting with horror to snakes.
  • Result: Within half an hour, the observed monkeys developed a fear of snakes through observational learning.
  • Follow-up experiments involved editing tapes to show horror reactions to various stimuli: flowers, a toy rabbit, a toy snake, and a toy crocodile.
  • Findings: The monkeys showed acquired fears of the toy snake and toy crocodile, but not the flowers or toy rabbit.
  • Conclusion: This pattern aligns with the preparedness hypothesis; snakes and crocodiles posed dangers to early primate ancestors, but flowers and rabbits did not (Ohman & Mineka, 2003).

Preparedness and Phobias

• Challenge to Equipotentiality:

  • A notable challenge to the principle that all stimuli can become conditioned fears equally.
  • Observation of Phobias in the General Population:
  • Common phobias include fear of the dark, heights, snakes, spiders, deep water, and blood.
  • Many individuals with these phobias lack frightening encounters with these stimuli.
  • In contrast, rare phobias exist for items like razors, knives, and electrical outlets, despite many having had negative experiences with them.

• Seligman's (1971) Preparedness Hypothesis:

  • Proposed that the distribution and prevalence of phobias can be explained by evolutionary preparedness.
  • Human ancestors faced threats from certain stimuli, like steep cliffs and poisonous animals, due to their potential dangers, shaping predispositions to fear these.
  • Conversely, household items posed no such threat.
  • Prepared fears are thus seen as emotional legacies from natural selection (McNally, 2015; Hofmann, 2008; Ohman & Mineka, 2001).

Learned Aversions and Taste Aversions

• Conditioned Taste Aversions in Rats:

  • Research by John Garcia and colleagues (Chambers, 2018) demonstrated biologically influenced conditioned taste aversions.
  • Experiment: Rats exposed to X-rays (causing nausea) developed aversions to specific tastes.
  • Result: They did not associate nausea with visual or auditory stimuli presented post-X-rays.
  • Conclusion: Rats associate nausea more readily with taste than with other sensory stimuli, highlighting adaptation to avoid toxic substances (Garcia & Koelling, 1966).

• Evolutionary Advantage of Conditioned Taste Aversions:

  • This phenomenon makes sense evolutionarily (O'Donnell et al., 2010).
  • Learning associations through first-hand experiences would be dangerous.
  • To avoid repeated experiences of food poisoning, organisms can learn aversions from one instance.
  • This aversion learning can occur even with a long time lag between eating (conditioned stimulus, CS) and illness (unconditioned stimulus, UCS), a deviation from typical classical conditioning norms.

• Conditioned Taste Aversions in Cancer Patients:

  • Chemotherapy often induces nausea and vomiting, causing aversions to food eaten before treatment, even when logically unrelated.
  • Health psychologists suggest patients eat a novel or less preferred scapegoat food before chemotherapy to condition aversions to that food instead of their preferred options (Andresen et al., 1990; Fischetti, 2014).

Case Study: Sauce Béarnaise Syndrome

• Seligman's Personal Experience:
  • Dr. Martin Seligman recounted a dinner incident where he consumed filet mignon with sauce béarnaise, which he enjoyed.
  • After experiencing nausea and illness hours later, he developed an aversion to sauce béarnaise, leading to a conditioned taste aversion towards that specific flavor (Seligman & Hager, 1972).
  • Discussion Point: Consider whether Seligman's experience contradicts classical conditioning principles (such as those illustrated by Pavlov's dog experiments).

Conclusion

• The principles of preparedness and learned aversions highlight the adaptive evolution of behavioral responses to potential threats, elucidating the complex nature of phobias and taste aversions in both animals and humans. The adaptability of learning has implications across various contexts, including healthcare and behavioral therapy.