This study evaluated the relative functions of pitch contours in infant-directed speech (IDS) by comparing it with adult- (ADS) and foreigner-directed speech (FDS). The shape of pitch contours derived from target words in speech samples was analysed using two novel algorithmic methods and a standard qualitative approach. Our findings indicate that IDS is very distinct from ADS and FDS, whilst the latter two exhibit a strong similarity to each other. These results suggest that pitch contours in IDS serve an emotional-attentional function rather than a linguistic function.