Testing the evolutionary theory of behavior dynamic's predictions about choice under concurrent random-ratio...

Area of Science:

• Behavioral Economics
• Psychology
• Evolutionary Theory

Background:

• The evolutionary theory of behavior dynamics (ETBD) posits specific predictions for choice behavior under concurrent random-ratio (RR) schedules.
• These predictions relate to how preference for denser schedules intensifies with greater ratio differences and smaller absolute ratio requirements.

Purpose of the Study:

• To empirically test the predictions of the ETBD concerning human choice under concurrent RR schedules.
• To investigate the influence of varying ratio differences and absolute ratio requirements on preference.

Main Methods:

• Sixty-three undergraduate students participated in a choice task involving two concurrently available response options on a touchscreen.
• Experimental conditions manipulated the difference between ratio requirements, while groups differed in the absolute ratio requirement of the denser option.

Main Results:

• Participant preference for the denser schedule increased as the difference between concurrent ratio requirements grew, supporting ETBD predictions.
• Groups with smaller absolute ratio requirements exhibited more extreme preferences, also consistent with ETBD.
• A notable level of heterogeneity in individual behavior was observed, contrasting with the uniformity of simulated ETBD organisms.

Conclusions:

• The study validates key predictions of the ETBD regarding concurrent ratio schedules and human choice.
• Findings underscore the significance of individual variability in behavioral research, which is not fully captured by current ETBD models.
• Future research should focus on individual differences and refine ETBD to account for human heterogeneity in choice behavior.