In a study by Dr Virginia Slaughter at the University of Queensland, Australia, a video was played to 36 toddlers in which a woman pointed to pictures of six coloured fish and counted them in a correct sequence. She then counted up to six again but pointed repeatedly at just two of the fish.
Half of the toddler group were 15 months and half 18 months old. Researchers found the 18-month-olds preferred the correct sequential counting as they watched it for longer, whereas the 15-month-olds did not have a preference.
Dr Slaughter, in the research published in the British Royal Society's journal Proceedings B, said this showed that 'by 18 months of age, infants have sufficient experience with their cultural counting routine to discriminate between correct and incorrect counting'.
To check that the children were not just following the finger moving, the counting was repeated in Japanese. This failed to grab the children's attention.
Early years expert Penny Tassoni called the findings 'great news'. She pointed to similar conclusions drawn by Elizabeth Spelke, professor of psychology at Harvard University, in 2000. Professor Spelke carried out a study with the psychologist Fei Xu which showed six-month-old infants can reliably distinguish between displays of eight and 16 dots. A further study in 2005 revealed they could tell the difference between 16 and 32.
She also claimed babies can track small numbers of objects and reason about what happens when one is added or taken away.
Ms Tassoni said the studies dismantle the myth that only a few people can 'naturally' do maths. 'We need to focus on how we support children of all ages in developing mathematical understanding.'