HUMANS do it, and so do chicks: we all count from left to right.
of Trento, Italy, and her colleagues trained chicks to find food rewards in either the fourth or sixth of 16 dispensers. Initially, reward dispensers were black while the empty ones were white. But they were gradually made to be white as well, which meant that the chicks had to 鈥渃ount鈥� to obtain the food.
For training, the dispensers were placed in a line pointing away from the chicks. The line was then turned 90 degrees so that the chicks faced all 16 at once, and had the choice of counting the dispensers from either the left or the right. The team found that the birds counted from the left, preferring to go to a dispenser fourth from the left, not the right (Biology Letters, ). The same was true for adult nutcracker birds.
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Rugani says animals and humans may instinctively count from the left because the right hemisphere of the brain 鈥� which processes the left field of vision 鈥� is dominant in visual tasks. This suggests counting from the left may be instinctive rather than culturally learned, say the team.