The claim
§8: “Bartlett’s serial reproduction experiments and Bayesian iterated-learning models both show that transmission is reconstructive and filtered by inductive biases rather than neutral copying.” The manuscript adds the data-processing inequality: information about the ancestor cannot increase along a Markov chain, even as later retellings become easier to process.
What it does not say
It does not say messages get less comprehensible along a chain; the manuscript is explicit that conventionalization can make them easier. Bartlett is unread here (LIT-768).
Evidence from human chains
Kalish, Griffiths and Lewandowsky (LIT-820) report human function-learning chains: 28 of 32 converged on a positive linear function, a bias stated before the experiment, mostly whatever the starting function. Two of the eight negative-start families ended on the negative linear function, which is partial counter-evidence. The prior was taken from earlier studies rather than measured on these learners.
Note of 2026-10-29: what holds it back
The claim’s general form, that transmission is filtered by the transmitters’ inductive biases, waits on a chain whose endpoint matches a prior measured on its own transmitters before transmission (QUESTION-137). THEORY-489’s chains converge on a bias taken from earlier studies and do not tell sampling learners from MAP learners. CASE-068’s priors were measured after the experiment (Moussaïd), or predict less than the received message (Jagiello and Hills). ARG-035, from the two readings the manuscript cites, is Proposed because it holds only for sampling learners.