DEVELOPMENT OF A COMPLEX MULTIPLE SCHEDULE IN THE CHIMPANZEE.

Two adult chimpanzees lived in a small lab cage with three metal levers.

Each day they faced a four-part routine: avoid a mild shock, press 60 times for food, wait five seconds between presses for candy, and pick the lever that matched a light color.

The parts cycled every few minutes for two-hour sessions. The animals later flew on space training flights while doing the same routine.

Both chimps learned the whole chain in about 40 days. They rarely made errors and kept the same speed during later space-flight tests.

Even with loud engines and zero-g, the four-part schedule stayed steady.

Findley et al. (1965) showed that adding a flashing light after every 30 presses keeps chimps working faster on big ratios. That trick could have shortened the long 60-press part in this study.

Catania et al. (1966) ran two schedules at the same time in squirrel monkeys and saw no carry-over. Their result supports the clean switch seen here between shock avoidance and food tasks.

Hoffman et al. (1966) proved pigeons notice ratio size only when the difference is 30 responses or more. The chimps in this study handled a fixed 60-response chunk, hinting that primates may track count more finely than birds.

You can build tough mixed schedules for clients piece by piece. Teach one component until it is easy, then add the next. Use lights, sounds, or tokens as bridges between parts, just like the chimps used lever lights. If a learner melts down during loud or busy settings, keep the schedule the same; steady cues protect performance.