It's also about some collective trust/fantasy, in addition to the tolerance.
For example, I don't think Tokyo is particularly safer than a (walkable) US city.
But since people there collectively believe Japan is a safe country and are proud of it, they let their child go out.
But I agree that the risk tolerance points too. I have talked to a handful of Japanese parents and none of them let their small kids go out without the supervision anymore. So the lower risk tolerance isn't a US-only problem. I guess it's a symptom of modernized society in general (although would love to be proven wrong.)
For example, I don't think Tokyo is particularly safer than a (walkable) US city. But since people there collectively believe Japan is a safe country and are proud of it, they let their child go out.
But I agree that the risk tolerance points too. I have talked to a handful of Japanese parents and none of them let their small kids go out without the supervision anymore. So the lower risk tolerance isn't a US-only problem. I guess it's a symptom of modernized society in general (although would love to be proven wrong.)