Discussion

Can sex, age, or previous experience explain a within-species variation in grey mouse lemurs?

Yes! The results showed that age explained a within-species variation in inhibitory control, and sex explained a within-species variation in causal understanding. These findings are in line with what could be expected from literature. When older animals make more errors in inhibitory control, this can be  best explained by decreased cognitive functions that have been found to occur in aged grey mouse lemurs.

Do captive grey mouse lemurs have better cognitive abilities than wild ones?

No, captive grey mouse lemurs did not have better cognitive abilities than wild grey mouse lemurs! However, the grey mouse lemur’s origin, meaning whether the individual is wild or captive-born, does explain a within-species variation in cognition. Surprisingly enough, it was the wild grey mouse lemurs that actually outperformed the captive ones in both problem solving and causal understanding!

Even though captive grey mouse lemurs were hypothesized to have better cognitive abilities than wild lemurs, there are potential explanations for the opposite findings. They may have to do with the different age structure of captive and wild study animals or with an increased behavioural flexibility of wild animals that experience a higher degree of environmental dynamics than their captive counterparts.