The paper explores the relationship between attachment processes and the development of the capacity to mentalize, or understand mental states in self and others. It suggests that mentalizing is a key determinant of self-organization, acquired in early social relationships. Evidence is reviewed showing that the quality of attachment relationships influences reflective function in both parents and children. A model is proposed where the caregiver's ability to understand the child's intentional stance is central to self-organization. The implications of this model for pathological self-development, particularly in cases of maltreatment, are discussed. Reflective function is the ability to interpret behavior in terms of mental states, enabling children to understand others' beliefs, feelings, and intentions. It is essential for affect regulation, impulse control, and self-monitoring. Reflective function is not the same as introspection, which focuses on conscious mental states, whereas reflective function is an automatic process that helps interpret others' actions. The development of reflective function is linked to the child's ability to understand mental states, which is influenced by early social interactions. The paper discusses how infants begin to develop a teleological stance, interpreting actions in terms of goals, and how this evolves into mentalizing. Representational mapping, the process of coordinating self and other representations, is crucial for this development. Attachment security is closely related to the development of reflective function. Secure attachment provides a foundation for the child to develop mentalizing abilities, as the caregiver's sensitivity and understanding of the child's mental states facilitate this process. The paper highlights the role of secure attachment in fostering the child's ability to understand and regulate emotions, as well as in the development of a coherent sense of self. The paper also discusses the role of social interactions, including pretend play and conversations about feelings, in the development of reflective function. These interactions provide opportunities for the child to understand mental states and develop a sense of self. The paper suggests that secure attachment may be a catalyst for the child's mentalizing skills, as it provides a supportive environment for the development of these abilities. The relationship between attachment and mentalizing is complex, with multiple pathways and mediators contributing to the child's development. The paper concludes that secure attachment is essential for the child's development of reflective function and mentalizing abilities, which are crucial for self-organization and emotional regulation.The paper explores the relationship between attachment processes and the development of the capacity to mentalize, or understand mental states in self and others. It suggests that mentalizing is a key determinant of self-organization, acquired in early social relationships. Evidence is reviewed showing that the quality of attachment relationships influences reflective function in both parents and children. A model is proposed where the caregiver's ability to understand the child's intentional stance is central to self-organization. The implications of this model for pathological self-development, particularly in cases of maltreatment, are discussed. Reflective function is the ability to interpret behavior in terms of mental states, enabling children to understand others' beliefs, feelings, and intentions. It is essential for affect regulation, impulse control, and self-monitoring. Reflective function is not the same as introspection, which focuses on conscious mental states, whereas reflective function is an automatic process that helps interpret others' actions. The development of reflective function is linked to the child's ability to understand mental states, which is influenced by early social interactions. The paper discusses how infants begin to develop a teleological stance, interpreting actions in terms of goals, and how this evolves into mentalizing. Representational mapping, the process of coordinating self and other representations, is crucial for this development. Attachment security is closely related to the development of reflective function. Secure attachment provides a foundation for the child to develop mentalizing abilities, as the caregiver's sensitivity and understanding of the child's mental states facilitate this process. The paper highlights the role of secure attachment in fostering the child's ability to understand and regulate emotions, as well as in the development of a coherent sense of self. The paper also discusses the role of social interactions, including pretend play and conversations about feelings, in the development of reflective function. These interactions provide opportunities for the child to understand mental states and develop a sense of self. The paper suggests that secure attachment may be a catalyst for the child's mentalizing skills, as it provides a supportive environment for the development of these abilities. The relationship between attachment and mentalizing is complex, with multiple pathways and mediators contributing to the child's development. The paper concludes that secure attachment is essential for the child's development of reflective function and mentalizing abilities, which are crucial for self-organization and emotional regulation.