SafetyInsights.org

Does exposure to uncheckable witness opinions and speculations and background info prior to the investigation bias the subsequent causal judgements from investigators? A new study suggests yes.

This study to be summarised soon experimentally evaluated the effects of providing background info and ‘uncheckable’ content (speculations, opinions, or judgements like ‘they’re lazy or reckless’ or work/drive unsafely), and whether this influenced how investigators subsequently evaluated the incident.

Key findings:

·        Biasing uncheckable information, like opinions, were found to affect participants’ judgements of event cause, and increased their ratings of witness confidence

·        Biasing background info about a worker affected participant judgements about event cause, the diagnostic value of the witness statement and the number of factual claims in the witness statement resulting in “more uncheckable claims being misclassified as potential facts”

·        “participants struggled at times to differentiate between checkable and uncheckable information”

·        “participants’ judgments were affected by both sources of bias but independently and not cumulatively”

Participants had trouble differentiating checkable vs uncheckable content.

They were more successful at identifying data which could be verified (more objective things like speed or physical objects) but had more trouble differentiating uncheckable opinions for checkable things.

Witnesses who were more confident were also rated by investigators as more credible.

The author argues that these findings “brings to the fore evidence of confirmatory, process-based bias”.

Here, people “harvest information that fits with their preconceived ideas, give greater weight to information that supports their existing belief, ignore or undermine contradictory information and reinterpreted information to support their theory”.

** Note a limitation is that the sample didn’t include professional investigators from what I can tell.

Authors: MacLean, C. L., & Miller, G. S. (2024). Journal of Safety Research, Volume 89

Study link: https://osf.io/preprints/psyarxiv/7vxu3/download

LinkedIn post: https://www.linkedin.com/posts/benhutchinson2_does-exposure-to-uncheckable-witness-opinions-activity-7136510067545182208-Q1xt?utm_source=share&utm_medium=member_desktop