# Ecological factors affecting prosociality in marmoset monkeys

## TL;DR

This study explores how short-term ecological factors influence prosocial behavior in marmoset monkeys.

## Contribution

The study reveals how food size and time since food access affect prosocial interactions in marmosets.

## Key findings

- Larger food portions consistently promoted prosocial interactions in marmosets.
- Longer durations since food access led to more individualistic behavior.
- There was no significant interaction between food size and time since food access.

## Abstract

Prosocial behaviors, such as cooperation and food sharing, are critical for maintaining group cohesion in social species, yet the influence of transient physiological states on these behaviors remains poorly understood. This study investigates how short-term ecological factors impact social behavior in common marmosets (Callithrix jacchus), a highly prosocial nonhuman primate species. Specifically, we tested how food divisibility (small vs. large food items) and time since food access (TSFA; 0 h, 1 h, and 3 h) influenced food sharing behavior. Results revealed that larger food portions consistently promoted prosocial interactions, while longer durations since food access shifted behavior toward individualism. No significant interaction effect between TSFA and food size was observed. These findings suggest that marmoset prosociality is sensitive to immediate ecological conditions, reflecting flexible, context-dependent social decision-making.