Similarities in brain size, life histories, psychology and behaviour in parrots, corvids and apes suggest that certain socio-ecological selection pressures may have driven the convergent evolution of cognition in these families. However, very little is known about parrot behaviour and cognition, outside of African greys and kea. Therefore, captive red-shouldered macaws (Diopsittaca nobilis) and black-headed caiques (Pionites melanocephala) were presented with a variety of tasks to assess their social and physical cognition and behavioural flexibility. Although these species possess many similarities in their life history and ecology, there are also substantial differences in their morphology and natural habitats that could have driven differences in their cognitive evolution. Observations of social and physical interactions in both species revealed that macaws engaged in high levels of affiliative behaviour, and object neophobia, whereas caiques displayed high levels of social play and object exploration. However, such differences did not appear to result in differences in their social or physical cognition. Macaws and caiques displayed comparable performances on Serial Reversal Learning tasks (as an index of behavioural flexibility). Both species also demonstrated similar performances on two Means-End transfer tasks and a series of innovative foraging tasks that were designed to assess their comprehension of object relationships. However, macaws and caiques appeared to solve such problems by generalising learned information across novel tasks. Overall, these findings suggest that these two species may approach certain socio-ecological problems using flexible cognition that may be generalised across different problems, supporting claims for a domain general intelligence.