For example, animals that live only a few days or a few years are often not very intelligent. In contrast, the most intelligent animals seem to live longer.
Is this true? Are there any studies to prove or disprove this statement?
Limiting the conversation to mammals, and taking relative brain size as a proxy for intelligence (which, of course is not necessarily "true", but at least is quantifiable), the answer is yes: body-size relative brain size correlates with body-size relative longevity in mammals.
using a global database of 493 species, we provide evidence showing that mammals with enlarged brains (relative to their body size) live longer and have a longer reproductive lifespan (González-Lagos et al.).
They present data by species in the paper, which is available free online, but so as to have something on SE, I've mocked up a chart based on the averages they give for each mammal order:
- González-Lagos C, Sol D, Reader SM. 2010. Large-brained mammals live longer. Journal of Evolutionary Biology 23: 1064–1074.