For the study, Franklin and her team showed photographs of 18 different babies—newborn, 3-month-old, and 6-month-old—to 142 adults. They then asked how willing each adult would be to adopt children, based on their perceptions of their happiness, health, and attractiveness. They found that 6-month-olds won the day, followed by 3-month-olds. The newborns were just not cute enough.
Researchers suspect that as babies become more able to tolerate illness at the 6-month mark, there is a delay in parent-child bonding in case the newborns don’t survive. Meanwhile, we are programmed to consider older children and toddlers to be the cutest, so that parents direct resources towards the offspring most likely to survive.
“Hunter-gatherers who already had a baby they were breastfeeding could not breastfeed two babies at once,” co-author Tony Volk, also of Brock University, said in a statement. “If you are a peasant mother in medieval England and you only have enough food for one child, and if having two means they both could die, it is best to have one child. These are difficult decisions that people have been making for thousands of years.”