Cognitive processes play an important role in human mate choice. However, far less is known about this topic in non-human animals. In this thesis, I take a comparative approach to sexually... Show moreCognitive processes play an important role in human mate choice. However, far less is known about this topic in non-human animals. In this thesis, I take a comparative approach to sexually selective cognition by studying humans (Homo sapiens) and Bornean orang-utans (Pongo pygmaeus). I start by reviewing the literature on sexually selective cognition. Hereafter, I show that visual, but not auditory or olfactory attractiveness, plays a major role in initial human mate choice. Furthermore, I show that attractiveness has a profound influence on visual attention in humans, and that attentional biases towards attractive conspecifics may be associated with mate choice. I explore the same topic in Bornean orang-utans by presenting them with stimuli of fully developed males or males experiencing arrested development. The results of these studies suggest that orang-utans preferentially attend to fully developed males, but only in the eye-tracking task and not in touchscreen tasks. The last chapter explores vocalisations, and suggests that orang-utan mate preferences might reflect in female vocal behaviour. Altogether, the results of this thesis suggest that humans and orang-utans show cognitive biases towards mate-relevant traits. However, better understanding of the link between such biases and actual mate choice remains of pivotal importance. Show less
Language is a uniquely human trait. All animals have ways to communicate, but these systems do not bear the same complexity as human language. However, this does not mean that all aspects of human... Show moreLanguage is a uniquely human trait. All animals have ways to communicate, but these systems do not bear the same complexity as human language. However, this does not mean that all aspects of human language are specifically human. By studying the language perception abilities of other species, we can discover which parts of language are shared. It are these parts that might have been at the roots of our language evolution. In this thesis I have studied language and music perception in two bird species, zebra finches and budgerigars. For example, zebra finches can perceive the prosodic (intonation) patterns of human language. The budgerigars can learn to discriminate between different abstract (grammar) patterns and generalize these patterns to new sounds. These and other results give us insight in the cognitive abilities that might have been at the very basis of the evolution of human language. Show less
