I could equally make cryonics success sound almost certain

I'd be interested to see someone do that.

There are a lot of variants on this exercise that could be studies in bias. The five of us doing this estimate on the bus, for example, realized that our answers came out clustered while Jeff's was far away because we had done it together. For each individual question we were supposed to think of our own answer before anyone spoke, to avoid anchoring. But we were anchored by the answers the others had given to all the previous questions.