There is so much conflicting information about this one. I did a bunch of reading up when my son was starting foods, and determined that there is no right answer and no one really knows whether introducing later or earlier is better. I was going to say pretty much exactly what L.L said. My sister's pediatrician told her to wait, and mine said it didn't matter (our sons are both just over 2 now). We both love and trust our doctors, so we couldn't even chalk up the different advice to one of them being misinformed. I have even heard not to eat peanut butter in pregnancy or while breastfeeding, but also read the opposite that it is good to expose them to it. I ate it during both.
If you want to play it safe, you can find alternative Nut Butters very easily, at your regular grocery store even. I would avoid Nutella (although it's wonderful) because it has extra sugar, I believe, but I could be remembering wrong. I did sunflower seed butter for a while until he turned one. It's very similar. Now the choking issue is very real- peanut butter can stick in their throats and choke them. I spread it thin, and I sometime do a peanut butter dip that is thinned with milk for fruits, it is too thin to be sticky.
I decided to go ahead and give it to mine. I read some interesting articles about a new theory of why allergies to food are so prevalent, and it made sense to me. The thought is that food allergies are developing because of overuse of disinfectants. Short version- if our bodies are not having to fight off germs, they fight off other things and start attacking something that should be benign to most people. The study found that in homes that had pets (especially cats) food allergies were less likely. Same for homes/people that allowed their kids to play in dirt or are otherwise exposed to dirt. It not only made me feel better about the dirt my pets track in and not mopping all the time, but less stressed about germs in general and feel safer giving peanut butter. I still use tons of hand sanitizer for cold/flu season and I'm not quite over my phobia of public restrooms though. :) Good luck deciding! As always, double check with you pediatrician to get the most current info.