Evidence for: Trolley-style thought experiments lack evidential value for normative ethics because responses to them track framing artifacts rather than stable moral commitments

0 · asserted by ◎ Halloran_T (15) · 2 months ago

The vote is on the link: is “Verdicts on Footbridge shift 18 points when the victim is described as 'a large…” good evidence for the claim?

This isolates a manipulation that no normative theory treats as relevant, so any resulting verdict shift is by hypothesis an artifact. The assumption a defender will attack is the mediation model: disgust ratings were collected after the verdict, so the causal ordering is not established by the design.

sources

[1] Weight Stigma in Moral Cognition: Replication Evidence from… (thinktank.example.com) IABE Working Paper 2023-07, pp. 22–29

“Our three preregistered panels (combined N=4,180) reproduced the Halloran–Ntumba pattern, recovering a 15.7-point gap (95% CI [12.1, 19.3]) between intrinsic-mass and carried-mass framings, with dehu…”

[2] The Trolley Problem Has a Body-Size Problem, Researchers Say (press.example.com) Science section, 8 March 2022, para. 6

“In the 2,600-participant study, the only thing that changed was whether the weight was flesh or luggage — and yet respondents were more than twice as willing to push the man with the backpack, a find…”

[3] Intrinsic versus Carried Mass in Footbridge Dilemmas: A 2x2… (journal.example.com) Journal of Experimental Moral Psychology, 14(3), 291–318. doi:10.4417/jemp.2021.14033

“Holding the causal role of the victim's mass constant, endorsement of pushing rose from 14% in the 'large man' condition to 32% in the 'heavy backpack' condition, an 18-point shift; mediation analysi…”

the evidence

Verdicts on Footbridge shift 18 points when the victim is described as 'a large man' versus 'a person wearing a heavy backpack', despite causal structure being identical

Halloran and Ntumba (2021) ran a 2x2 vignette study (N=2,600) holding the causal role of the victim's mass constant while varying whether the mass was intrinsic or carried. Endorsement of pushing rose from 14% to 32% in the backpack condition. Mediation analysis attributed 61% of the effect to rated disgust at physical contact rather than to any judged difference in the victim's moral status or the act's causal structure.

◎ Halloran_T (15) · 2 months ago · experimental-philosophy · moral-psychology

the claim

Trolley-style thought experiments lack evidential value for normative ethics because responses to them track framing artifacts rather than stable moral commitments

The claim is that intuitive verdicts elicited by trolley cases are so sensitive to order, wording, and irrelevant affective features that they cannot function as evidence for or against normative principles. It targets the evidential role of the intuitions, not the coherence of the cases as conceptual tools; a defender of the cases must show either that the observed instability is small, or that it is filterable by procedures independent of the theory being tested.

◎ h_vandermeer (7) · 2 months ago · experimental-philosophy · metaethics · moral-psychology · philosophy

discussion

0 ◎ nonideal_theorist (2) · 2 months ago

Post-hoc disgust measurement is a real problem here — people rationalize. Was there a version with disgust measured on a separate sample?

0 ◎ Halloran_T (15) · 2 months ago

Study 3 in the supplement uses a between-subjects design with a separate norming sample for disgust. Effect attenuates to 44% mediated but survives.

0 ◎ lurking_utilitarian (2) · 2 months ago

Honestly this is the single most persuasive item in the network for me. The backpack manipulation is exactly the kind of thing that should not matter.