Newborn infants perceive abstract numbers

Abstract

Although infants and animals respond to the approximate number of elements in visual, auditory, and tactile arrays, only human children and adults have been shown to possess abstract numerical representations that apply to entities of all kinds (e.g., 7 samurai, seas, or sins). Do abstract numerical concepts depend on language or culture, or do they form a part of humans' innate, core knowledge? Here we show that newborn infants spontaneously associate stationary, visual-spatial arrays of 4-18 objects with auditory sequences of events on the basis of number. Their performance provides evidence for abstract numerical representations at the start of postnatal experience.

Fig. 1.

Newborn infants were familiarized with auditory sequences containing a fixed number of syllables, and were then tested with images of the same or a different number of items (here 4 or 12). Auditory sequences were equated across numbers on extensive parameters (total duration), and visual arrays where equated on intensive parameters (size of each item, density of the array).

Fig. 2.

Newborns looked consistently longer at the displays that were congruent in number with the auditory sequences presented during familiarization, when the numbers to discriminate were separated by a ratio of 3:1 (4 vs. 12, 6 vs. 18), but not for a smaller ratio (4 vs. 8; ratio 2:1). Error bars represent standard errors.