In the early years of life, interactions between mother and child are crucial for child development. So far, these interactions have primarily been examined in terms of socio-emotional sensitivity. However, drawing on psychological and (early) educational theories as well as over 1900 video recordings, this work demonstrates that cognitive activation represents an additional independent dimension of interaction behavior in children aged 7 to 17 months: mothers who interact with socio-emotional sensitivity do not automatically engage in cognitively activating interactions. This interaction behavior enables the child to perform more complex actions and explore their environment more effectively. Both dimensions are hardly dependent on background characteristics such as the mother's educational level in the first year of life, whereas in the second year, this changes.