Cognitive bias in animals

[3] Cognitive biases have been shown in a wide range of species including rats, dogs, rhesus macaques, sheep, chicks, starlings and honeybees.

[3] One study on rats investigated whether changes in light intensity – a short-term manipulation of emotional state – has an effect on cognitive bias.

Up to five million pet dogs in the UK, approximately 50% of the population, may perform undesirable separation-related behaviour when left home alone.

[10] One study shows that restriction of collared peccaries (Pecari tajacu) in metabolism pens affects their emotional state and increases faecal glucocorticoid (a stress hormone) metabolite concentrations.

Immediately after training, half of the honeybees were subjected to vigorous shaking for 60 s to simulate the state produced by a predatory attack on a concealed colony.

This shaking reduced levels of octopamine, dopamine, and serotonin in the hemolymph of a separate group of honeybees at a time point corresponding to when the cognitive bias tests were performed.

Therefore, agitated honeybees display an increased expectation of bad outcomes similar to a vertebrate-like emotional state.

The researchers of the study stated that, "Although our results do not allow us to make any claims about the presence of negative subjective feelings in honeybees, they call into question how we identify emotions in any nonhuman animal.

It is logically inconsistent to claim that the presence of pessimistic cognitive biases should be taken as confirmation that dogs or rats are anxious but to deny the same conclusion in the case of honeybees.