[leppr]

I don't think the over evaluation part of the Dunning-Krueger effect has much to do with evolution. Basically it is a fundamental physical limitation: if you've never even seen an obstacle you can't say whether you could jump over it or not. After that it's just the natural optimism that's required by all species on earth to do anything non-trivial, nothing special. The under evaluation part is more interesting though, why not just keep going?