Brain favours round number over fractions, scientists find
HUMAN brains have trouble working out fractions and should stick to round numbers, according to researchers.
The confusion is such that 52.47 per cent is sometimes perceived as being lower than 50 per cent, they found.
In one experiment, volunteers thought a fictitious cure for Covid-19 that claimed to be 90 per cent effective was seen as better than one that claimed to be 91.27 per cent effective
And in another test, they thought someone who scored 80 per cent in an exam had done better than another person who got 81.47 per cent.
The calculating confusion may explain why shops prefer to advertise sales in round numbers: 50 per cent off, for instance, rather than 52.74 per cent off – even if the round number is less than the exact one.
Our brains prefer round numbers because they can be processed quickly and their relationship to the “ideal 100 per cent” is worked out more speedily.
Tests on round versus non-round numbers were carried out on 1,500 volunteers by researchers from the Rensselaer Polytechnic Institute, New York.
The data means those trying to communicate a positive message should use a round number, even if the figure is not as impressive as the exact number. Although researchers said the opposite could be true, for example when trying to inform people of the dangers of smoking.
The study found that the message “7.69 per cent of children alive today will die from smoking” worked better than when the figure was changed to “around 8 per cent”, even though the latter is a bigger number. This is because round numbers enhance the value of a product or service, while more precise numbers devalue it, the researchers told the specialist journal Organizational Behaviour and Human Decision Process. In this case, the precise number devalues smoking.
Gaurav Jain, an assistant professor of marketing, said: “Managers and public health officials should be careful when using non-round numbers because the use of this approach in communicating messages may decrease the subjective evaluations of the target on the associated attributes.”