The intersection between alexithymia, testosterone reactivity, and coparenting in fathers predicts child's prosocial behavior

The development of prosocial skills in children is a key predictor of long-term social, cognitive, and emotional functioning. However, the role of fathers ' psychological characteristics in fostering prosocial development, including during the prenatal period, and the mechanisms underlying their influence, remain relatively unexplored. This study aimed to examine whether a higher tendency of alexithymia, a difficulty to identify and verbalize emotions, in expectant fathers predicts prosocial behavior of two -year -old toddlers through the quality of coparenting and whether greater testosterone increase during a stressful parenting task moderates this indirect effect. A sample of 105 couples and their children was tracked longitudinally starting from the third trimester of pregnancy (T1), at three months (T2), and at two years postnatally (T3). Using self -report questionnaires, fathers reported on alexithymia (T1) and mothers and fathers reported on coparenting quality (T2). Additionally, fathers provided saliva samples before and after engaging in a stressful parenting task (the Inconsolable Doll Task) to measure testosterone reactivity (T1). Children 's prosocial behavior was observed during an out -of -reach task (T3). A moderated mediation analysis using structural equation modeling showed that higher levels of alexithymia pre -birth predicted lower coparenting quality three months after birth, which in turn predicted lower prosocial behavior of two -year -old children, but only among fathers with mean or high testosterone increases. This study illuminates a potential mechanism by which fathers ' alexithymia and testosterone reactivity forecast their toddlers ' prosocial behavior.