# Reward value shapes the time course of self-bias

## TL;DR

This study shows that the value of owned items affects how quickly and strongly people favor their own possessions over others' in decision-making.

## Contribution

The study reveals that reward value influences the time course and strength of self-bias in object classification.

## Key findings

- Self-prioritization was stronger for high-value items compared to low-value items.
- The facilitatory effect of self-bias lasted longer for high-value items.
- Reward value dynamically modulates decisional bias in object classification tasks.

## Abstract

Personal possession wields a potent influence on decision-making, such that objects owned-by-self are categorized more speedily than comparable items belonging to other people. The temporal characteristics of this self-prioritization effect, however, are little understood. Notably, it is uncertain whether the duration of self-bias is sensitive to the characteristics of owned objects, particularly when the items have implications for the self-concept. Accordingly, using an object-classification task, here we explored the extent to which a theoretically important stimulus-related factor—reward value—influences the time course of self-bias. Across three experiments, participants classified high- and low-value items (i.e., stones [Exp. 1], cryptocurrencies [Exp. 2 & 3]) that allegedly belonged to self and a friend. A consistent pattern of effects was observed, indicating that reward value moderated both the extent and persistence of self-prioritization. Specifically, although self-prioritization emerged for both high- and low-value items, this facilitatory effect was larger and more enduring for the former (vs. latter) stimuli. These findings highlight the dynamic character of decisional bias, with implications for theoretical accounts of self-function.

The online version contains supplementary material available at 10.3758/s13421-025-01763-4.