Altering the proportion of components in a mixed fixed-ratio schedule.

The team mixed two fixed-ratio schedules in one session. Birds had to peck ten times on most trials. Sometimes they had to peck one hundred times.

The scientists changed how often the big hundred-response ratio appeared. They watched how long birds paused after food and when they started pecking again.

When the big FR100 came up less than one time in twenty, pauses got shorter. The birds also spread their early pecks more evenly.

Dropping the share of heavy work below twenty-to-one reshaped the whole response pattern.

Mahoney et al. (1971) set the stage. They showed that chaining moderate FR chunks (64-128 responses) gives the steadiest pace. The 1973 study moved from chunk size to schedule odds.

Young et al. (2017) added another layer. They proved that the size of the next food reward also changes pause length. So both ratio odds and reward size steer the break.

Crossman et al. (1985) looked like a contradiction. Tiny FR1-FR7 schedules made pauses shrink as the ratio grew. The clash clears up when you see the 1985 birds never faced the heavy FR100 load that drove the long pauses in 1973.

If you run mixed-ratio programs for fluency or endurance, keep the hard trials rare. Drop them below one in twenty and you will see shorter post-reinforcement pauses and smoother starts. Use this when shaping extended work with clients who shut down after big efforts.