Do contingency-conflicting elements drop out of equivalence classes? Retesting Sidman's (2000) theory

Area of Science:

• Behavioral psychology
• Learning theory
• Stimulus equivalence

Background:

• Sidman's theory of stimulus equivalence posits that conflicting elements in a reinforcement contingency are excluded from an equivalence class.
• Minster et al. (2006) challenged this by finding that conflicting reinforcers do not drop out of equivalence classes.

Purpose of the Study:

• To investigate the role of the developmental order of stimulus relations in conditional discrimination performance.
• To assess whether establishing stimulus-reinforcer relations before conditional relations influences the maintenance of equivalence classes.

Main Methods:

• Experimental manipulation of the developmental order of stimulus relations (stimulus-reinforcer vs. conditional relations).
• Assessment of conditional-discrimination performance and accuracy.
• Analysis of stimulus-reinforcer and conditional relations within equivalence classes.

Main Results:

• The study replicated findings by Minster et al. (2006), indicating that conflicting reinforcers do not drop out of equivalence classes.
• Developmental order of stimulus relations did not appear to be a significant factor in maintaining accuracy on baseline conditional relations.
• Evidence suggests that 'dropping out' may be better interpreted as the formation of differentiated subclasses.

Conclusions:

• The findings support and extend previous research challenging Sidman's original theory of stimulus equivalence regarding conflicting elements.
• The developmental order of establishing stimulus relations may not be critical for performance in conditional discrimination tasks.
• The results have implications for understanding the differential outcomes effect and the complex dynamics within equivalence classes.