two experiments were carried out involving 40 animals of rha/lu and rla/lu strains in a one-way active avoidance situation. subjects were tested for avoidance conditioning and activity with seven behavioural measurements under training for three days and, under the effect of d-amphetamine sulfate for 5 days. in the first experiment, subjects were selected to form strain-sex groups to ascertain strain and sex differences. sex differences emerged only on activity scores. in the second experiment, subjects were all female and were tested under two levels of ucs footshock. shock differences demonstrated a consistent effect with the higher shcok value evoking a larger number, and faster responses.