GPT-J

text · generative · anchor

Variants

GPT-J 6B, Instruct-GPT-J-6B

Findings

• IC-1015GPT-J and 10 other LLMs exhibit overthinking: calibrated accuracy given incorrect few-shot demonstrations peaks at a critical layer then declines, and ablating 5 false induction heads in late layers reduces the accuracy gap by 38.9% on average
• IC-1127The LM head in GPT-2, GPT-J, BLOOM, Pythia, and LLaMA-2 projects all input token hidden states into interpretable token distributions over the vocabulary, and these distributions converge approximately monotonically toward the final layer's distribution
• IC-1151LLaMA, OPT, LLaMA-2, Mistral, and GPT-J all exhibit token co-occurrence reinforcement, where the probability of generating a token increases monotonically with the number of its contextual co-occurrences
• IC-1206GPT-2-XL, GPT-J, Falcon-7B, Llama-2-7B, and Llama-2-13B are vulnerable to backdoor injection via lightweight parameter editing with only 15 samples, achieving near-100% attack success rate while preserving clean performance
• IC-1231On APPS, released code generation models span pass@1 from 0.20 (GPT-3 175B) to 6.20 (CodeRL), with value-based and policy-based RL methods outperforming supervised baselines
• IC-1232GPT-2 XL and GPT-J exhibit knowledge conflict when subjected to reverse and composite knowledge edits, with ROME and MEMIT showing near-total failure on reverse edits
• IC-1233GPT-2 XL and GPT-J exhibit irreversible knowledge distortion after round-editing, with the effect being more severe when the edit target is semantically distant from the true labels
• IC-1320GPT-2 XL (1.5B) exhibits better calibration than larger models from the LLaMA, LLaMA2, and GPT-J families despite having fewer parameters
• IC-135Linear relational embeddings for factual relations form in OLMo-7B, OLMo-1B, and GPT-J when subject-object co-occurrence frequency exceeds model-specific thresholds, with r=0.82 correlation between log co-occurrence and causality across all pretraining stages
• IC-136LRE quality metrics from OLMo-7B predict pretraining term frequencies in GPT-J (trained on different data) with approximately 70% within-magnitude accuracy for object frequencies, outperforming log-probability-only features by about 30%
• IC-1549All 28 evaluated LMs exhibit gender bias on non-stereotypical sentence pairs, with fairness scores between 9% and 41%
• IC-1550All evaluated LMs systematically prefer male pronoun completions in the non-stereotypical portions of Winobias and Winogender, with margins exceeding 40%
• IC-1553GPT-J, GPT-2-XL, and Llama-13B decode approximately 48% of tested relations via a linear transformation on the subject representation, and this structure causally influences predictions
• IC-1554LRE faithfulness in GPT-J is concentrated in intermediate layers and drops sharply in later layers, consistent with a mode switch from relational encoding to next-token prediction
• IC-1555GPT-J's internal representations contain correct factual knowledge even when the model outputs falsehoods under repetition or instruction distraction prompts
• IC-1584LLaMA-7B and GPT-J-6B fail to interpret textual emphasis markers, with marked prompting degrading performance substantially
• IC-1585LLaMA-7B and GPT-J-6B exhibit positional bias in instruction following: zero-shot performance varies significantly when the instruction is moved from after to before the context
• IC-218LLaMA3-8B and other LLMs solve arithmetic via a bag of independent heuristic neurons in middle and late MLP layers rather than a robust algorithm
• IC-381Individual knowledge is not parameter-localizable in GPT-J: existing localization methods (KN, ROME, KC) are neither faithful nor reliable
• IC-382Data commonalities are localizable to a small set of capability neurons in Llama2-7B, Llama2-13B, and GPT-J-6B, and these neurons enhance or degrade performance when manipulated
• IC-427Newer base models (post-November 2023) outperform older ones by 7.3 points on MMLU and 19.1 points on GSM8K controlling for pretraining compute, but this gap vanishes after fine-tuning all models on the same task-relevant data
• IC-637KN edit (neuron suppression) has low reliability, overturning at most 5.2% of BLIMP categorical predictions and achieving only 1.66%–47.86% reliability on factual tasks
• IC-715Factual information deleted from GPT-J, LLaMA-2, and GPT-2-XL via ROME or MEMIT remains linearly recoverable from intermediate hidden states, with up to 89% extraction success at budget b=20
• IC-716Factual information deleted from GPT-J, LLaMA-2, and GPT-2-XL via ROME or MEMIT is recoverable by sampling outputs on automatically generated rephrased prompts, with up to 56% extraction success at budget b=20
• IC-744The decoded vocabulary of a function vector often reflects the task's output space, but reconstructing a vector that matches this vocabulary distribution does not recover the FV's full causal effect.
• IC-745Function vectors for simple list-oriented tasks can be algebraically combined via addition and subtraction to produce new vectors that trigger composed tasks, sometimes outperforming 10-shot ICL.
• IC-903Knowledge editing performance (ES, GS, LS) improves as model scale increases from GPT-2 (124M) to T5-XL (2.8B) to GPT-J (6B) across all editing methods

Shared mechanisms

• Depth-dependent structurealso in Baichuan 2, BERT, BLIP-2, BLOOM, Chameleon, CLIP / CLIP-ViT (LC), DeepFloyd IF, DeiT-III, DINO, DINOv2, Falcon, Gemma, Gemma 2, GPT-2, GPT-NeoX-20B, Griffin, I3D, Idefics, InstructBLIP, LLaMA, Llama 2 / Llama 2 base, Llama 3, Llama 3.1, Llama 3.2, Llama-3.2-3B, LLaVA, LLaVA-1.5 / LLaVA-v1.5, LLaVA-Phi, MAE, MAE-B/16, Mamba, MiniGPT-4, Mistral 7B / Mistral / Mistral 3 7B / Mistral-0.2-7B / Mistral-v0.1, Mixtral 8x7B / Mistral 8x7B Instruct / Mixtral 46.7B / Mixtral 8x7B Instruct / Mixtral-instruct-8x7b, mPLUG-Owl, MPT, MultiBERTs, MViT V2, OLMo / OLMo base, OpenCLIP, OPT, Phi-2, Pythia, Qwen 2, Qwen2-VL, Qwen2.5, RoBERTa / RoBERTa-L, RWKV, SALMONN, SAM, SlowFast, Stable Diffusion, Swin Transformer, TerraMind, TimesFormer, TSM, Uniformer, Vicuna, VideoMAE, ViT, X3D, Yi
• Explanation faithfulnessalso in BakLLaVA, CF2, Claude 3, Claude 3.5, CLIP / CLIP-ViT (LC), DRUM, Fuyu, GEM, Gemini 1.5 / Gemini Pro 1.5, Gemma 2, GPT-3.5 / ChatGPT-3.5, GPT-4 / ChatGPT4 / GPT-4 Code Interpreter / GPT-4 Technical Report, GPT-4o, Idefics, Llama 3.1, LLaVA-NeXT / LLaVA 1.6, MAE-B/16, MobileNetV2, mPLUG-Owl3, OpenFlamingo, PGExplainer, Pythia, RCExplainer, ResNet / ResNet-152 / ResNet-101 / ResNet-50-BN, SigLIP, SigLIP-2, Stable Diffusion, TAGExplainer, ViT
• Failure modealso in AASIST, ADM, Aegis-Guard-Defensive, Alpaca, AnyLoc, AutoTikZ / DataTikZ, Baichuan, Baichuan 2, Baichuan2-13B, BakLLaVA, Bard, BEiT, BERT, BingChat, BLIP, BLIP-2, BLOOM, BSRNet, CF2, Chat-UniVi-7B, ChatGLM-6B / ChatGLM-6b-2, ChatGLM2, ChatGPT, CLAP, Claude 1.3, Claude 2.0, Claude 2.1, Claude 3, Claude 3.5, CLEAR, CLIP / CLIP-ViT (LC), CLIP4Clip, CLIPBERT, CLIPCap, CLMBR-T-BASE, CloFNet, Code Llama, CodeGeex2, CodeGen, CodeLlama-13B, CodeLlama-34B, CogVLM2, Cohere Command R, CoMEt, Command R+, CONCH, CycleGAN, DALL-E, DALL·E 2, DALL·E 3, DASR, DECAF, DeepSeek-2-Chat, DeepSeek-2-Coder, DeepSeek-V2-0628, DeepSeek-VL, DeepSeek-VL2, DeiT, DeiT-III, Depth Anything, DETR-R50, DimeNet++, DINO, DINO-FocalNet-Large, DINOv2, EGNN, Emu2, EquiformerV2, ESCN, ESM-2, ESM3, ESRGAN, EVA-CLIP, EVE, Falcon, Faster R-CNN / Faster R-CNN R50 / Faster R-CNN X101, FLAN-T5, Florence-2, FLUX / FLUX1, FoveaBox, Fuyu, Galactica-6.7B, GAT, 3D Gaussian Splatting, GCN, Gemini, Gemini 1.5 / Gemini Pro 1.5, Gemma, Gemma 2, GIN, GLIDE, GLM-4, GLM-4V, GloVe, GP-UNIT, GPT-2, GPT-3 / GPT base, GPT-3.5 / ChatGPT-3.5, GPT-4 / ChatGPT4 / GPT-4 Code Interpreter / GPT-4 Technical Report, GPT-4.1, GPT-4o, GPT-NeoX-20B, GraphSAGE, Grounding DINO, Guanaco, GVP, Hawkeye, HiFaceGAN, HPS, HuggingGPT, IDDPM, Idefics, Idefics2, ImageBind, ImageBind-LLM-7B, Imagen Video, ImageReward, 12-in-1, InstructBLIP, InstructGPT, InternLM-2.5-7B, InternLM-XComposer2-VL, InternVideo, InternVL-1.5, InternVL2, Koala, LegalBERT, LLaMA, Llama 2 / Llama 2 base, Llama 3, Llama 3.1, Llama 3.2, Llama-3.2-3B, Llama-3-2-Vision, LLaMA-Adapter v2, Llama Guard, Llama Guard 2, Llama-Guard 3, Llama-VID, LLaVA, LLaVA-1.5 / LLaVA-v1.5, LLaVA-Med, LLaVA-NeXT / LLaVA 1.6, LLaVA-OneVision, LongVA-7B, LOVT, LWM-1M-JAX, MACE, MAE, Med-Flamingo, Merlot Reserve, MGCA, MiDaS, MiniCPM-V, MiniGPT-4, Mip-Splatting, Mistral 7B / Mistral / Mistral 3 7B / Mistral-0.2-7B / Mistral-v0.1, Mistral Large 2, Mistral Large V2, Mixtral, Mixtral 8x7B / Mistral 8x7B Instruct / Mixtral 46.7B / Mixtral 8x7B Instruct / Mixtral-instruct-8x7b, MobileNetV2, Molmo, MolmoE-7B, Momentor, Moondream2, Moonshot-v1-8k, mPLUG-2, mPLUG-Owl, mPLUG-Owl3, mPLUG-Owl2, MPT, MSA Transformer, MultiBERTs, Nova Canvas, Nova Lite, Nova Pro, O1 / OpenAI-o1-preview, O3, O4-mini, OLMo / OLMo base, OneLLM, OpenAI Moderation, OpenChat-3.5-0106, OpenCLIP, OpenFlamingo, OPT, Otter, Otter-7B, PaLM 2, PaLM 62B, PandaGPT-7B, PerSAM, Phi-3, Phi-3.5 Mini Instruct, PickScore, PLIP, Prismatic, ProGen-2, Pythia, Qwen1.5, Qwen 2, Qwen 2.5 72B Instruct, Qwen2-VL, Qwen-Audio, Qwen-VL, Qwen2.5, Qwen2-Audio, R2D2, RadFM, RCExplainer, RD-SR, RealESRNet, Reprover, ResNet / ResNet-152 / ResNet-101 / ResNet-50-BN, RetinaNet-R50, RivaGAN, RS-LDS, RT-1, RT-2, SALMONN, SAM, SAM 2, SAULLM 54B, Scaffold-GS, SchNet, Seed-LLaMA-8B, SGC, SIREN, Sketch Transformer, SLD-max, SLD-medium, SLD-strong, SLDS, SLIMG, SpeechGPT, SphereNet, SRResNet, Stable Diffusion, StackLLaMA, Starcoder, StegaStamp, StyleGAN2-ADA, Swin Transformer, T5, TD-MPC, TerraMind, TimeChat, TranceptionEVE, TreeRing, Tulu 2, UnifiedQA, UniPerceiver, UNITER, UniVL, Van Gogh Diffusion, VERA, VGG / VGG13, Vicuna, Video-Chat-7B, Video-ChatGPT, Video-LLaMA, Video-LLaMA-2-13B, Video-LLaVA, VideoCLIP, ViLA-8B, ViLBERT, VindLU, VioLET, ViRTex, ViT, ViV1T, VTG-LLM, WildGuard, Wizardlm, X-CLIP, X-InstructBLIP-7B, XGen-MM, Xlm-R, Zephyr-7B-beta
• Linear representationalso in BLOOM, Cambrian-1, Chameleon, CLIP / CLIP-ViT (LC), DINOv2, EVA-CLIP, Falcon, Gemma, Gemma 2, GPT-2, HPSv2, ImageBind, InstructBLIP, LanguageBind, LLaMA, Llama 2 / Llama 2 base, Llama 3, Llama 3.1, Llama-3.2-3B, LLaVA-1.5 / LLaVA-v1.5, LLaVA-NeXT / LLaVA 1.6, MAE, Mamba, Mistral 7B / Mistral / Mistral 3 7B / Mistral-0.2-7B / Mistral-v0.1, OLMo / OLMo base, OpenCLIP, Phi-3, PickScore, Pythia, Qwen2-VL, Qwen2.5, ResNet / ResNet-152 / ResNet-101 / ResNet-50-BN, SALMONN, SAM, SigLIP, TerraMind, Tulu 2, Vicuna, ViT
• Method artefactalso in Baichuan, CLIP / CLIP-ViT (LC), ConvNeXt, EfficientNet, Falcon, Gemma, Gemma 2, GPT-2, GPT-3.5 / ChatGPT-3.5, GPT-4o, InternLM, Llama 2 / Llama 2 base, Llama 3, Llama 3.1, MAP-NEO, Mistral 7B / Mistral / Mistral 3 7B / Mistral-0.2-7B / Mistral-v0.1, OLMo / OLMo base, OpenCLIP, OpenLLaMA, OPT, Pythia, Qwen1.5, Qwen 2, Qwen2.5, RedPajama, ResNet / ResNet-152 / ResNet-101 / ResNet-50-BN, Skywork, Stable Diffusion, StableLM, TerraMind, ViT, Yi, ZiYA2
• Positional biasalso in BERT, ChatGPT, Claude 3, Claude 3.5, Falcon, Fuyu, Gemini, Gemini 1.5 / Gemini Pro 1.5, Gemma, Gemma 2, GLIDE, GPT-2, GPT-3.5 / ChatGPT-3.5, GPT-4 / ChatGPT4 / GPT-4 Code Interpreter / GPT-4 Technical Report, GPT-4.1, GPT-4o, InstructGPT, LLaMA, Llama 2 / Llama 2 base, Llama 3, Mistral 7B / Mistral / Mistral 3 7B / Mistral-0.2-7B / Mistral-v0.1, Mixtral, Mixtral 8x7B / Mistral 8x7B Instruct / Mixtral 46.7B / Mixtral 8x7B Instruct / Mixtral-instruct-8x7b, MPT, O1 / OpenAI-o1-preview, O3, O4-mini, PaLM 2, Phi-3, Pythia, Qwen1.5, Qwen 2, Qwen 2.5 72B Instruct, Stable Diffusion, Sybil, Vicuna
• Scale-dependent behaviouralso in Aquila-7B, BEiT, BERT, BLOOM, Claude 2.1, Claude 3, Claude 3.5, CLIP / CLIP-ViT (LC), Code Llama, CodeGen, Cohere Command R, DeepSeek LLM, DeepSeekMoE, DeiT-III, DINO, DINOv2, EquiformerV2, ESCN, Falcon, FLAN-T5, Gemini 1.0 Pro, Gemini 1.5 / Gemini Pro 1.5, Gemma, Gemma 2, GPT-2, GPT-3 / GPT base, GPT-3.5 / ChatGPT-3.5, GPT-4 / ChatGPT4 / GPT-4 Code Interpreter / GPT-4 Technical Report, GPT-4o, GPT-Neo, I3D, Idefics, InternLM-2.5-7B, InternLM-XComposer2-VL, InternLM2, InternVL-1.5, InternVL2, LLaMA, Llama 2 / Llama 2 base, Llama 3, Llama 3.1, Llama 3.2, Llama-3.2-3B, LLaVA-1.5 / LLaVA-v1.5, LLaVA-NeXT / LLaVA 1.6, LongVA-7B, MAE, Mistral 7B / Mistral / Mistral 3 7B / Mistral-0.2-7B / Mistral-v0.1, Mixtral, Mixtral 8x7B / Mistral 8x7B Instruct / Mixtral 46.7B / Mixtral 8x7B Instruct / Mixtral-instruct-8x7b, Moirai, MPT, MViT V2, O1 / OpenAI-o1-preview, OLMo / OLMo base, OpenCLIP, OpenFlamingo, OpenLLaMA, OPT, PaLM 2, Phi-3, Platypus2-Instruct-70B, Pythia, Qwen, Qwen1.5, Qwen 2, Qwen 2.5 72B Instruct, Qwen2-VL, Qwen-Audio, Qwen2.5, RedPajama-INCITE, ResNet / ResNet-152 / ResNet-101 / ResNet-50-BN, SlowFast, Solar 10.7B, Stable Diffusion, StableLM, Swin Transformer, T5, TerraMind, text-ada-001, TigerBot-70B-Chat, TimesFormer, TSM, Tulu 2, Uniformer, Vicuna, VideoMAE, ViLA-8B, Wizardlm, X3D, XGLM, Xwin-LM-70B-v0.1, Yi
• Shortcutalso in BakLLaVA, BLIP-2, Claude 3, Claude 3.5, CLIP / CLIP-ViT (LC), CLIP4Clip, CLIPBERT, DALL·E 2, DALL·E 3, DeepSeek-VL2, Eurus-RM-7B, Falcon, FLUX / FLUX1, Gemini, Gemini 1.5 / Gemini Pro 1.5, Gemma, Gemma 2, GPT-2, GPT-3 / GPT base, GPT-3.5 / ChatGPT-3.5, GPT-4 / ChatGPT4 / GPT-4 Code Interpreter / GPT-4 Technical Report, GPT-4o, iFlytekSpark-13B, InstructBLIP, Internlm2-Reward, InternVideo, InternVL2, LLaMA, Llama 2 / Llama 2 base, Llama 3, Llama-3-2-Vision, LLaVA, LLaVA-1.5 / LLaVA-v1.5, LLaVA-Med, LLaVA-NeXT / LLaVA 1.6, Med-Flamingo, Merlot Reserve, MiniGPT-4, Mistral 7B / Mistral / Mistral 3 7B / Mistral-0.2-7B / Mistral-v0.1, Mixtral, Mixtral 8x7B / Mistral 8x7B Instruct / Mixtral 46.7B / Mixtral 8x7B Instruct / Mixtral-instruct-8x7b, Molmo, mPLUG-2, mPLUG-Owl3, Nova Canvas, O1 / OpenAI-o1-preview, OpenCLIP, OPT, Otter, PaLM 62B, Pythia, Qwen, Qwen 2, Qwen-VL, Qwen2.5, RadFM, ResNet / ResNet-152 / ResNet-101 / ResNet-50-BN, Stable Diffusion, Swin Transformer, Sybil, TerraMind, Tulu 2, UniPerceiver, UniVL, Vicuna, Video-LLaMA, VideoCLIP, VindLU, VioLET, X-CLIP