This paper discusses two user studies to investigate whether human cognitive differences affect user interaction and visual behavior within recognition-based graphical authentication tasks. In order to increase external validity, we conducted the studies with separate user samples. In the first study (N = 82) which embraced a longitudinal and ecological valid interaction scenario, we examined whether field dependence-independence (FD-I) differences have an effect on their login performance. During the second study (N = 51) which embraced an in-lab eye tracking setup, we investigated whether FD-I differences of participants are reflected on their visual behavior during graphical key creation. Analysis of results revealed interaction effects of users’ FD-I differences which indicate that such human cognitive differences should be considered as additional human design factors in graphical user authentication research.