Some factors that influence the acquisition of complex, stereotyped, response sequences in pigeons.

Researchers let two pigeons peck four keys in any order they wanted. Every sequence earned food, so no pattern paid better than another. The birds faced over 720,000 chances, day after day.

The team watched which orders the birds picked. They wanted to see if equal rewards would keep behavior varied or push it into a rut.

Both birds soon locked into one favorite key-peck dance. They repeated the same long chain again and again, even though every other chain paid the same.

The rigid loops looked like superstitious rituals. Equal reinforcement did not create variety; it built a single, complex habit unit.

Fabbretti et al. (1997) extend this finding. They showed pigeons like two separate keys more than one big key, even when key size is equal. Free choice itself is reinforcing, so birds settle into one pattern because the act of choosing feels good.

Aragona et al. (1975) seems to disagree. On concurrent VR schedules pigeons spread responses to maximize pay. Here, with free sequences, they do the opposite: they stereotype. The difference is schedule type. VR schedules reward speed; free sequences reward any order, so variety gives no extra gain.

Pierce et al. (1983) followed up one year later. They built a rate-constancy model showing pigeons treat long chains as single response units. That model explains why the 1982 birds stuck with one mega-chain: they acted as if they had only one lever labeled "do the whole dance."

Your learner may lock into one response path even when many options pay off. If you run choice-based programs, rotate materials, vary locations, or add differential pay to keep behavior flexible. Watch for ritual loops in free-play or DTT; they may signal the task needs fresh splits or new reinforcers.