Abstract: Helping behavior, a typical form of prosocial behavior, refers to voluntary actions in which individuals attend to and assist others in escaping from undesirable situations. Early childhood represents a critical period for the frequent occurrence of helping behaviors in young children. Although various factors influence children's helping behaviors, emotion may serve as a key factor. Individual emotional experiences encompass not only the emotional valence dimension (positive vs. negative) but also the emotional response orientation dimension (self oriented vs. other-oriented). However, little is known about how emotional valence and emotional response orientation jointly influence helping behaviors and the underlying neural mechanisms in young children. Therefore, this study systematically investigated these questions through three experiments.
In Experiment 1 (N = 259, M = 5.48 years, SD = 0.76 years, 127 boys), 4- to 6-year-old participants were randomly assigned to positive, neutral, or negative emotion conditions. We used the gift paradigm to induce corresponding emotions and then examined helping behaviors using a spilled-pencils task. Building on Experiment 1, Experiment 2 (N = 180, M = 5.39 years, SD = 0.79 years, 98 boys) randomly assigned 4- to 6-year-old participants to positive or negative emotion groups, with emotional induction under two emotional response orientation conditions (self-oriented vs. other-oriented). Participants then completed the spilled-pencils task. Building on Experiment 2, Experiment 3 (N = 34, M = 5.38 years, SD = 0.33 years, 17 boys) focused on the neural mechanisms underlying the effect of emotional valence on 5-year-old children's helping behaviors under self-oriented conditions. Five-year-old participants were randomly assigned to self-oriented positive or self-oriented negative emotion groups. After emotion induction using the gift paradigm, helping behaviors were examined in the hill paradigm involving puppet characters displayed on screen, while functional near-infrared spectroscopy (fNIRS) was used to record brain activation throughout the process.
Experiment 1 revealed that compared to negative and neutral emotions, positive emotions significantly promoted helping behaviors in young children aged 4 to 6 years. Experiment 2 found that other-oriented negative emotions elicited more helping behaviors than self-oriented negative emotions, whereas no significant difference was observed between self-oriented and other-oriented positive emotions. Experiment 3's fNIRS data revealed differentiated neural activation patterns underlying helping behaviors under self-oriented emotional conditions in 5-year-old children. Under self-oriented negative emotions, children's helping behaviors were accompanied by higher activation in the dorsolateral prefrontal cortex (DLPFC), whereas under self-oriented positive emotions, helping behaviors were accompanied by higher activation in the middle temporal gyrus (MTG).
These findings indicate that helping behaviors are influenced not only by emotional valence but also moderated by emotional response orientation. Under self-oriented negative emotions, 5-year-old children's helping behaviors may primarily rely on a cognitive control pathway, whereas under self-oriented positive emotions, helping behaviors may primarily rely on an empathy-altruism pathway. These findings have important implications for understanding the development of prosocial behavior in early childhood.

Key words: helping behaviors in young children, emotional valence, emotional response orientation, functional near-infrared spectroscopy (fNIRS), dorsolateral prefrontal cortex (DLPFC), middle temporal gyrus (MTG)