Why it is a question
CLAIM-430 says an interaction can make available a way of relating the participants’ perspectives did not hold, and CLAIM-429 says a durable change acts on the coupling, not only the state. Neither says how to tell, in a person or a relationship, which happened. The existing evidence does not separate them: contact reduces prejudice and often generalizes (LIT-1413), narrative exchange outlasts argument (CASE-147), but neither isolates a change in how outcomes revise the interpretation.
What would count as an answer
A5’s contrasts, each holding the favourable information fixed:
- Information against cooperation. Does taking part change later behaviour more than equivalent favourable information?
- One-sided favour against mutual coordination. Does reciprocal responsiveness matter beyond the act?
- Local against general. Does cooperation change responses to other members of the category (CASE-146)?
- Belief against authority. Do participants endorse different propositions, or change whose testimony can move their later judgements (CLAIM-403’s stages)?
- Immediate against reproduced. Do changes survive separation, conflict and return to the original social setting?
Measured, A5 added, by conduct and not only self-report: behaviour toward unfamiliar group members, responses to disconfirming evidence, and willingness to grant epistemic standing, scored by evidence that does not pass through the interpretation under test (CLAIM-342). A5 also proposed an order manipulation: cooperation then debate, against debate then cooperation, since framing operations need not commute (CLAIM-052).
An answer at the level of states, if every effect is reproduced by a changed starting point with fixed coupling, would defeat CLAIM-429.
Note of 2026-10-29: the contact review and the field experiments, read
Two works this question leans on are now read, and neither supplies its contrasts.
- Paluck, Green and Green, LIT-1420 (NOTE-1393). On randomized evidence with delayed outcomes, “contact reduces prejudice” holds in direction and is qualified in size: 0.25 for ethnic and related targets, near zero in the pre-registered field trials. “Often generalizes” (LIT-1413, Unavailable) is untested there: the review’s outcomes mostly concern the group met, and its pooling does not separate generalization to the group from generalization to other groups. No included study isolates taking part from receiving information.
- Kalla and Broockman, LIT-1407 (NOTE-1396), behind CASE-147. In Experiment 2 a stranger’s video narrative did as well as both parties telling stories, so the contrast between information and cooperation is not the one its arms draw. It measures no behaviour and no generalization to other groups.
The question is unchanged and stays Open.
Note of 2026-10-29: a behavioural outcome, and a meta-analysis without one
- Scacco and Warren, LIT-1831 (NOTE-1418). It meets the measurement demand: conduct scored by incentivized, private, sealed games, which do not pass through the interpretation under test, and its stranger rounds are the “unfamiliar group members” the question names. It does not draw the first contrast: there is no arm with favourable information and none without taking part, since the course arms differ in whom one took part with, not in whether one took part. Its result for “local against general” is split: the effect toward strangers holds for Christians and not overall. And it adds a contrast the question lacks, same-group against cross-group taking part, since same-group cooperation itself moved conduct, toward more discrimination. The earlier note’s “near zero in the pre-registered field trials” is, for this study, which Paluck et al. count among their three pre-registered trials, a null on attitudes beside a positive result on behaviour; its registration is dated seven months after the endline, though before the researchers had the outcome data.
- Lemmer and Wagner, LIT-1836 (NOTE-1419). No help on the measurement demand: no behavioural outcome could be included. On “local against general”, the outcomes reach the whole target outgroup and unspecified ethnic outgroups, but no comparison measured a specific outgroup not involved, so generalization to the category is supported and generalization beyond it untested, as NOTE-1393 found for its sample. On the question’s third part, between studies, programmes in which participants only read or watch cross-group friendships did no worse than those in which they took part, on immediate self-reports; there is no comparison within a study.
The question is unchanged and stays Open.
Note of 2026-10-29: Cernat 2011, from its abstract
Cernat 2011, LIT-1829, was registered as a candidate for this question’s third part. It is Unfetched and unread, and this note rests on its abstract and the method text a search engine indexes. All three arms read, and none takes part, so it cannot tell taking part from receiving information of equal favourable content. What it varies is the content: whether the Roma exemplar’s friend in the story belongs to the reader’s own group (a Romanian) or to another outgroup (a Bulgarian). Per the abstract, the outgroup–outgroup story was enough to improve attitudes toward Roma, and the ingroup–outgroup story did more, through group emotions. That bears on what “equal favourable content” would have to match if the contrast were drawn: whether the information shows one’s own group in the relation. On the measurement demand it adds nothing: the measures the abstract names are attitudes, anxiety, norms and emotions, none of them conduct.
The third part still has no within-study test. The question is unchanged and stays Open.