Big brains are not enough: performance of three parrot species in the trap-tube paradigm

The trap-tube task has become a benchmark test for investigating physical causality in vertebrates. In this task, subjects have to retrieve food out of a horizontal tube using a tool and avoiding a trap hole in the tube. Great apes and corvids succeeded in this task. Parrots with relative brain volumes comparable to those of corvids and primates also demonstrate high cognitive abilities. We therefore tested macaws, a cockatoo, and keas on the trap-tube paradigm. All nine parrots failed to solve the task. In a simplified task, trap tubes with a slot inserted along the top were offered. The slot allowed the birds to move the reward directly with their bills. All but one individual solved this task by lifting the food over the trap. However, the parrots failed again when they were prevented from lifting the reward, although they anticipated that food will be lost when moved into the trap. We do not think that the demanding use of an external object is the main reason for the parrots’ failure. Moreover, we suppose these parrots fail to consider the trap’s position in the beginning of a trial and were not able to stop their behaviour and move the reward in the trap’s opposite direction.     

Multidimensional influences of anxiety and assessment type on task performance

We examined state evaluation anxiety, trait evaluation anxiety, and neuroticism in relation to New Zealand first-year university students’ (n = 234) task performance on either a...     

The effects of psychological interventions on well-being measured with the Mental Health Continuum: a meta-analysis

Journal of Happiness Studies - The last decades experienced a rapid growth in the number of studies examining the effects of psychological interventions on well-being, yet well-being is often...