It's not that you need to ask it to be honest, it's that the defaults are kind of stupid and obnoxiously sycophantic. ChatGPT is also prone to getting stuck on particular ideas. If you're using the vanilla personalities without a custom prompt, not aware of and working against its issues, and not starting new chats occasionally you won't get good results. You'll get good-sounding garbage.
Part of my custom prompt is
```When using factual information beyond what I provide, verify it when possible.
When researching factual questions—especially by relying on papers and studies—actively look for null findings, negative results, and contradictory evidence, not just positive or confirmatory findings.```
To me, the most interesting result of that part of my prompt is that in thinking mode, it ends up re-checking it's assumptions and sources fairly often. It's not about honesty, but correctness.
A custom prompt isn't the be-all end-all either. The right kind of questioning is important, and you also need to get a fresh context when you ask new questions or if you want to double check something.
Part of my custom prompt is ```When using factual information beyond what I provide, verify it when possible. When researching factual questions—especially by relying on papers and studies—actively look for null findings, negative results, and contradictory evidence, not just positive or confirmatory findings.```
To me, the most interesting result of that part of my prompt is that in thinking mode, it ends up re-checking it's assumptions and sources fairly often. It's not about honesty, but correctness.
A custom prompt isn't the be-all end-all either. The right kind of questioning is important, and you also need to get a fresh context when you ask new questions or if you want to double check something.