Monkeys display classic signatures of human symbolic arithmetic

Comparing children’sHomo sapiensand chimpanzees’Pan troglodytesquantity judgments of sequentially presented sets of items

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Bears ‘count’ too: quantity estimation and comparison in black bears, Ursus americanus

(2012) Jennifer Vonk et al.   ANIMAL BEHAVIOUR

Large quantity discrimination by North Island robins (Petroica longipes)

(2012) Alexis Garland et al.   ANIMAL COGNITION

Symbolic representation of number in chimpanzees

(2009) Tetsuro Matsuzawa   CURRENT OPINION IN NEUROBIOLOGY

Individual differences in non-verbal number acuity correlate with maths achievement

(2008) Justin Halberda et al.   NATURE

Summation and quantity judgments of sequentially presented sets by capuchin monkeys (Cebus apella)

(2007) Michael J. Beran et al.   AMERICAN JOURNAL OF PRIMATOLOGY