When Counterfactual Debiasing Backfires: Identity Cues as Task-Dependent Evidence in Harmful Language Understanding

Jia Duan, Xiaoyu Lu, Wenjing Hu, Zihao Ding


Abstract
Counterfactual debiasing is often used to reduce reliance on identity-linked shortcuts in harmful language understanding. We show that the same intervention can be harmful when identity mentions are not shortcuts but label-defining evidence. In multi-task cyberbullying modeling, identity cues may be spurious for cyberbullying detection (CD) and sentiment analysis (SA), yet necessary for fine-grained target identification (TI). We propose task-aware routing, which sends CD and SA through a debiased representation while preserving the original representation for TI. We evaluate this approach on the English-translated BullyExplain benchmark, HateXplain, and an external Measuring Hate Speech diagnostic. Experiments show that task-aware routing improves TI, while auxiliary detection and sentiment performance remain largely unchanged where applicable. Ablation studies attribute this improvement to representation routing that preserves identity-bearing evidence for TI rather than to class-weighting choices, with reduced-architecture diagnostics suggesting that the effect is not specific to the graph-enhanced model. These results support a task-conditional view of counterfactual debiasing: the same identity cue can warrant suppression in one task and preservation in another.
Anthology ID:
2026.emnlp-main.1062
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
24392–24410
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1062/
DOI:
Bibkey:
Cite (ACL):
Jia Duan, Xiaoyu Lu, Wenjing Hu, and Zihao Ding. 2026. When Counterfactual Debiasing Backfires: Identity Cues as Task-Dependent Evidence in Harmful Language Understanding. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 24392–24410, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
When Counterfactual Debiasing Backfires: Identity Cues as Task-Dependent Evidence in Harmful Language Understanding (Duan et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1062.pdf