Pigeon concept formation: successive and simultaneous acquisition.

Researchers taught pigeons to tell when a person was in view.

Some birds learned the rule one picture at a time (successive).

Others saw person and no-person photos side-by-side (simultaneous).

After training, the team tested new angles and new people to see if the birds still got it right.

Both groups reached high accuracy.

Birds trained one-by-one could still pick the person when photos were later shown together, and the other way round.

The birds also passed tests with brand-new pictures and orientations, showing they had learned a true concept, not just memorized photos.

Cohen et al. (1990) extended this work by adding more features.

They showed pigeons can master a category that needs five cues at once, proving the birds can handle richer concepts than the simple person/no-person task.

Williams et al. (2002) pushed speed limits, finding pigeons can judge same-versus-different arrays after only two seconds of viewing.

Together these follow-ups say: once a basic concept procedure works, you can pile on more features or cut viewing time and the birds still learn.

For BCBAs, the big lesson is flexibility.

Whether you present targets one after another or side-by-side, learners can still grasp the concept and use it in new situations.

If a client isn’t progressing with one arrangement, you can switch to the other without re-teaching from scratch.

The cross-procedure transfer also reminds us to test for generalization early; a few probe trials with new materials can show whether the learner has the concept or just the specific exemplars.