The family is often regarded as the primary and most basic unit of socialization and a very important determinant to the development of children's behavior and personality. The main aim of this study is to investigate the relationship between Personality Traits in Single Parenting Dynamic and Pro-social behaviors in highs choolers in Lagos State, Nigeria. 255 participants were used for this study and were administered test instruments, using Prosocial Self-Regulation Questionnaire, Self-Report Altruism Scale, and Big Five Inventory-10. The result of the study revealed that that there was a significant negative relationship between extraversion (r = -.178, P<.001) and Altruism Development. While an insignificant relationship was observed between altruism development and other dimensions of Personality Traits of Single Parents. Secondly, result of the study revealed that there was a significant positive relationship between Self-Regulation of respondents (r = .335, P<.001) and conscientiousness personality trait.. The study therefore concludes by positing that specific personality traits exhibited by single parents such as openness, conscientiousness, and emotional stability significantly influence the development of pro-social behaviors in their children. High schoolers raised in supportive and nurturing single-parent environments tend to demonstrate higher levels of altruism and self-regulation, suggesting that the emotional and psychological climate established by single parents plays a crucial role in shaping their children's social behaviors