In the master's thesis we looked at the theory of attachment and its transfer from childhood to adulthood. The aim of our method was to discover the traits within attachment theory that are present in childhood and later in adulthood. Based on previous research and sources, we hypothesized that there are categories that are beneficial to attachment and that inhibit attachment. The research was conducted using the method of semi-structured interviews we conducted. The analysis of these interviews was done using the Strauss-based grounded method. The participants in the research were between 25 and 45 years old, who lived in Ljubljana and its surroundings and Gorenjska. The analysis of the results was performed according to the principle of grounded theory according to Strauss. The results confirmed to us the connection between attachment needs, that children’s needs are repeated later in adult life. Childhood attachment can be described through two categories, which are childhood factors beneficial for contact and childhood breakup factors, while adulthood attachment can be described by partnership beneficial factors for contact and partnership breakdown factors. Thus, based on the analysis of the results, we can conclude that within attachment we have positive categories and negative categories that form attachment styles. These positive and negative categories are found in both childhood and adulthood.