KÄSTNER (2015)

• Aim: 

  To assess the role of the 5HTT gene when exposed to beneficial experiences in mice
• Method:

  • Lab experiment with male mice
  • IV: Presence/absence of positive experience (cohabitation with female)
  • DV: Anxiety-like behaviors and exploratory behavior
• Procedure:

  Kästner's study compared wild-type and knockout mice (normal vs. reduced 5-HTT expression) in two conditions: with or without female cohabitation. They measured anxiety and exploratory behavior to examine how genetic differences and environmental experiences interact to affect behavior.
• Results:

  • Beneficial experience (mating opportunity) only affected knock-out mice
  • These mice showed reduced anxiety and increased exploration
  • Mice with functioning 5HTT gene showed no behavior change
• Conclusion:

  • 5HTT gene may be a plasticity gene, not just a vulnerability gene
  • Susceptibility to beneficial experiences depends on 5HTT genotype
  • Weak version of 5HTT leads to more positive outcomes with beneficial experiences
• Strengths:

  1. Established cause-effect relationship between gene and behavior
  2. High control and replicability
  3. Ethical alternative to human gene manipulation studies
• Limitations:

  1. Generalizability to humans is uncertain
  2. Need for correlational studies in humans
• Ethical considerations:

  • Animal studies allow gene manipulation not possible in humans
  • Justification: potential benefits to human understanding outweigh animal welfare concerns