Wired:

Daniel Weary, an applied animal biologist at the University of British Columbia, and his colleagues have been working for decades to help improve the lives of dairy cattle. His practical studies have found ways to better feed and house cows and provided farmers with advice to help them decide the best practices for their animals — but he’s also demonstrated that dairy cows possess surprising intelligence and emotional sensitivity.

In a new study, Weary and his colleagues investigated how calves are affected by the emotional pain of separation from their mother and the physical pain of dehorning. The researchers found both types of pain can result in a negative cognitive bias similar to pessimism.