Comparing Gender Bias in Lexical Semantics and World Knowledge: Deep-learning Models Pre-trained on Historical Corpus

This study investigates the impact of continued pre-training transformer-based deep learning models on historical corpus, focusing on BERT, RoBERTa, XLNet, and GPT-2. By extracting word representations from different layers, we compute gender bias embedding scores and analyze their correlation with human bias scores and real-world occupation participation differences. Our results show that BERT, an encoderonly model, achieves the most substantial improvement in capturing human-like lexical semantics and world knowledge, outperforming traditional static word vectors like Word2Vec. Continued pre-training on historical data significantly enhances BERT’s performance, especially in the lower-middle layers. When historical human biases are difficult to quantify due to data scarcity, continued pre-training BERT on historical corpora and averaging lexical representations up to the 6th layer provides an
accurate reflection of gender-related historical biases and world knowledge.