Figure 2.

The left side compares the number of days to reach criterion in FR-1 and FR-4 appetitive shaping for control versus restrained males. There were no differences between restrained and control males. The right side compares the number of days to reach criterion in FR-1 and FR-4 appetitive shaping for control versus restrained females. The data show that restrained females reached criterion significantly faster than did control animals and that males reached all criterions faster than females.