Less means more for pigeons but not always

Area of Science:

• Behavioral Economics
• Animal Cognition
• Decision-Making

Background:

• Humans often exhibit the "less-is-more" effect, devaluing a set of high-quality items when combined with lower-quality items.
• This suboptimal decision-making has also been observed in other species like monkeys and dogs.

Purpose of the Study:

• To investigate whether pigeons exhibit the "less-is-more" effect in food choice tasks.
• To explore the influence of hunger levels on this decision-making behavior in pigeons.

Main Methods:

• Pigeons were presented with choices between single food options and combined food options.
• Experiment 2 manipulated the pigeons' food restriction levels to assess its impact on choice behavior.

Main Results:

• Normally hungry pigeons chose optimally, preferring a combination of preferred and less-preferred food over a single preferred food.
• Pigeons on a less-restricted diet demonstrated the suboptimal "less-is-more" effect, devaluing the combined food option.
• Control trials ruled out item novelty as the cause of the suboptimal choices.

Conclusions:

• Pigeon's food choice behavior can be optimal or suboptimal depending on their hunger level.
• The "less-is-more" effect in pigeons may stem from the devaluation of combined options when less-restricted, potentially due to increased motivation altering perceived value differences.