The prevailing hypotheses for the evolution of cognition focus on either the demands
associated with group living (the social intelligence hypothesis (SIH)) or ecological …

Highlights•Reliability and certainty interact to determine when learning should
evolve.•Reliability and frequency of events determine when prepared learning should …

There is remarkable diversity in brain size among vertebrates, but surprisingly little is known
about how ecological species interactions impact the evolution of brain size. Using guppies …

There is remarkable diversity in brain anatomy among vertebrates and evidence is
accumulating that predatory interactions are crucially important for this diversity. To test this …

Many genes are subject to contradictory selection pressures in males and females, and
balancing selection resulting from sexual conflict has the potential to substantially increase …

Brain size varies dramatically among vertebrates, and selection for increased cognitive
abilities is thought to be the key force underlying the evolution of a large brain. Indeed …

The brain is one of the most energetically expensive organs in the vertebrate body.
Consequently, the energetic requirements of encephalization are suggested to impose …

The social intelligence hypothesis (SIH) posits that within-group interactions drive cognitive
evolution, but it has received equivocal support. We argue the SIH overlooks a major …

Animal personalities range from individuals that are shy, cautious, and easily stressed (a
“reactive” personality type) to individuals that are bold, innovative, and quick to learn novel …

Complex evolutionary dynamics have produced extensive variation in brain anatomy in the
animal world. In guppies, Poecilia reticulata, brain size and anatomy have been extensively …