A good time to leave?: the sunk time effect in pigeons

Area of Science:

• Animal Behavior
• Behavioral Economics
• Cognitive Science

Background:

• The sunk time effect, or persistence in a losing course of action due to prior investments, is poorly understood in nonhuman animals.
• Previous research has primarily focused on human decision-making, leaving a gap in comparative animal cognition.

Purpose of the Study:

• To investigate the sunk time effect in pigeons (Columba livia).
• To determine the factors influencing persistence versus escape behavior in a controlled experimental setting.

Main Methods:

• Pigeons chose between two keys: one offering food after a fixed interval (FI) or no food (Extinction), and another to escape the trial.
• The durations of FI and Extinction schedules were systematically varied.
• Trials were equiprobable, unsignaled, and alternated randomly.

Main Results:

• Pigeons exhibited the sunk time effect by persisting through Extinction intervals.
• The absolute duration of the fixed interval did not influence the choice to persist or escape.
• The ratio between the fixed interval and Extinction durations was the key determinant of persistence.

Conclusions:

• Pigeons demonstrate sensitivity to relative time investment, not absolute time, when making decisions under conditions analogous to the sunk time effect.
• This study provides evidence for the sunk time effect in a nonhuman animal, expanding our understanding of decision-making biases across species.