An experimental analysis of verbal imitation in preschool children.

The researchers sat preschoolers at a table. An adult said an English word like "book" and waited.

If the child copied the word, they got candy and praise. If they said nothing, nothing happened.

Later the adult said Russian words the kids had never heard. No candy followed these copies. The team flipped the reinforcement on and off to see what would stick.

When the English copies paid off, kids also started nailing the unpaid Russian words.

When the candy stopped, both English and Russian copies dropped. Reinforcement spread from taught words to untaught ones.

Tullis et al. (2022) saw the same spill-over with instructive feedback in DTT: reward some answers, watch new ones pop up.

Dressel et al. (2019) seems to disagree. They blocked kids from whispering to themselves and still got the spill-over. Their null result hints that echoing out loud may not be the engine.

The two papers clash only on the pathway, not the outcome. Baron et al. (1968) shows echo practice helps; Dressel et al. (2019) shows it is not required. Both can be true if other routes exist.

STAATROSS et al. (1962) came first, proving that tokens plus candy boost early reading sounds. The new study swaps text for imitation and still finds the power of extrinsic reward.

You can grow a wider echoic pool without drilling every single word. Pick a handful of strong targets, pour on reinforcement, and listen for surprise copies to bloom. If a child stops echoing, bring the candy back and the whole set usually returns.