Recently several large language models (LLMs) have demonstrated their capability to generate a message in response to a user request. Such scientific breakthroughs promote new perspectives but also some fears. The main focus of this study is to analyze the written style of one LLM called ChatGPT 3.5 by comparing its generated messages with those of the recent US presidents. To achieve this objective, we compare the State of the Union addresses written by Reagan to Obama with those automatically produced by ChatGPT. We found that ChatGPT tends to overuse the lemma "we" as well as nouns and commas. On the other hand, the generated speeches employ less verbs and include, in mean, longer sentences. Even when imposing a given style to ChatGPT, the resulting speech remains distinct from messages written by the target author. Moreover, ChatGPT opts for a neutral tone with mainly positive emotional expressions and symbolic terms (e.g., freedom, nation). Finally, we show that the GPT's style exposes distinct features compared to real presidential addresses.

本研究针对大型语言模型（LLMs）在生成信息时的写作风格进行分析，特别是ChatGPT 3.5与历任美国总统的国情咨文演讲的比较。研究发现，ChatGPT过于使用名词和逗号，并且倾向于产生长句和中性语调，尽管尝试强加特定风格，但生成的内容依然与目标作者的风格存在显著差异。这一发现揭示了GPT在风格上与真实总统演讲的不同特征，提示了其在政策沟通中的潜在影响。 

白宫的幽灵作家：GPT的写作风格分析