The longer mice have lived with humans, the smarter they've become, study suggests

OTTAWA -- New research suggests that mice have evolved to handle living in a world that has been altered by humans.

The German study, published this week in Proceedings of the Royal Society B, looked at three subspecies of wild house mice and found the subspecies that has lived in human contact the longest – as long as 13,000 years – performed highest in a series of cognitive tests, while the subspecies that has lived with humans for the shortest -- as little as 3,800 years -- performed the weakest.

“These results cannot be explained by differences in neophilia, higher motivation or longer interaction with test set-ups, nor by better inhibitory control but rather mice appear to have evolved enhanced cognitive abilities to cope with the challenges of human-altered habitats,” the researchers from the Max Planck Institute for Evolutionary Biology in Germany wrote in the report.

In total, the researchers tested 148 mice, equally distrusted across the three subspecies and tested them using seven food-extraction tasks that required the mice to complete

Overall, the subspecies of mice that have lived with humans the longest were most likely to complete the tasks, while the subspecies who lived with humans for the least were least likely to complete the tasks.

“Our results show that house mice evolved enhanced cognitive abilities during their commensal life with humans,” the study notes.

“Cognitive abilities and especially innovative problem-solving may thus be key factors for animals to thrive in human-altered habitats. With urban environments increasing rapidly, how wild animals adjust to the challenges of living in close proximity to humans becomes increasingly more relevant, and an understanding of the traits that adapt and their underlying mechanisms will be key.”