Claims

For many organisms and ecological niches, general-purpose intelligence is not adaptive because it does not pay to be intelligent; there are more direct, efficient solutions to environmental problems than general-purpose learning mechanisms.

In ecological niches where the environment is static, where intelligence would be prohibitively expensive, or where organisms are short-lived, it is evolutionarily very difficult to evolve general-purpose learning mechanisms; specialized solutions tailored to specific problems are strongly favored instead.

For many creatures, it does not pay to be intelligent because general-purpose intelligence is not actually adaptive; in static niches, in environments where intelligence is expensive, or for short-lived organisms, evolving a specialized tailor-made solution is superior to evolving a general-purpose learning mechanism.