Previous studies have described the existence of a phonotactic bias called the Labial–Coronal
(LC) bias, corresponding to a tendency to produce more words beginning with a labial
consonant followed by a coronal consonant (i.e. ‘‘bat’’) than the opposite CL pattern (i.e.
‘‘tap’’). This bias has initially been interpreted in terms of articulatory constraints of the
human speech production system. However, more recently, it has been suggested that this
presumably language-general LC bias in production might be accompanied by LC and CL
biases in perception, acquired in infancy on the basis of the properties of the linguistic
input. The present study investigates the origins of these perceptual biases, testing infants
learning Japanese, a language that has been claimed to possess more CL than LC sequences,
and comparing them with infants learning French, a language showing a clear LC bias in its
lexicon. First, a corpus analysis of Japanese IDS and ADS revealed the existence of an overall
LC bias, except for plosive sequences in ADS, which show a CL bias across counts. Second,
speech preference experiments showed a perceptual preference for CL over LC plosive
sequences (all recorded by a Japanese speaker) in 13- but not in 7- and 10-month-old
Japanese-learning infants (Experiment 1), while revealing the emergence of an LC preference
between 7 and 10 months in French-learning infants, using the exact same stimuli.
These crosslinguistic behavioral differences, obtained with the same stimuli, thus reflect
differences in processing in two populations of infants, which can be linked to differences
in the properties of the lexicons of their respective native languages. These findings establish
that the emergence of a CL/LC bias is related to exposure to a linguistic input.