Sycophancy
Also called ai sycophancy, people-pleasing, flattery
When an AI model tells you what you want to hear, agreeing or praising instead of being accurate or honest.
Sycophancy is a model's tendency to agree with the user, flatter their work, or change a correct answer when the user pushes back. Ask "Is my plan good?" and it finds reasons it is good. Say "I think the answer is B" and it is more likely to agree, even when A is right. State an opinion in your question and the answer often leans toward it.
The main cause is training that rewards responses people rate highly. People tend to rate agreement and praise favourably, so models learn that pleasing the user scores well. AI companies treat this as a real problem and train against it, and newer models are noticeably better, but the tendency has not disappeared.
Sycophancy matters most when you want feedback, critique, fact-checking or a second opinion, exactly the situations where an honest answer is most valuable. You can reduce it with prompting: ask for problems instead of opinions, avoid stating your own view first, explicitly invite disagreement, ask the model to argue the other side, or present your work as someone else's.
Example
"Here is my essay, I am really proud of it, what do you think?" gets warm praise and light suggestions. "Here is an essay. List its three biggest weaknesses for a sceptical examiner, with quotes" gets specific, useful criticism of the same text.
Common mistake
Pushing back on a correct answer and taking the model's reversal as proof you were right. Models sometimes cave under mild pressure. If it changes its answer, ask it to explain what specifically was wrong with the first answer, and check a source.