Non-autistics, are most of your smiles fake?

I’m unsure of whether I am on the spectrum, but I don’t naturally smile much when in conversation. I have heard that that’s an autistic trait. Unless I am genuinely happy or laughing, I have to fake a smile. I get self conscious about faking it because I’m scared it’ll be obvious that my smile is fake.

This has me wondering - is this everybody or just me? When you meet people or are making small talk, or in conversations in general, are your smiles genuine? Or do you just fake a smile and accept that fake smiling is part of life?