It is undeniable: puppies are universally considered cuter and more pleasing to look at than their parents. They win us over with their big eyes, soft faces and infantile features. The young of the animal kingdom face extreme challenges every day, and being attractive to the adults of their own species is an advantage — but why are they also irresistibly appealing to us humans?

According to Konrad Lorenz, the father of modern ethology, there is a genuine schema, known as the "baby schema", that can explain our fondness for babies and young animals. The scientist attributes this attraction to a set of physical characteristics common across various species: a large head with a small face relative to the skull, big round eyes, small ears, a short muzzle, chubby cheeks, short and stubby limbs, rounded shapes and soft skin — completed by a clumsy gait and behaviour that is invariably playful.

These characteristics are thought to increase the survival chances of young animals and can sometimes lead adult animals to care for the young of different species. Numerous scientific experiments carried out over the years have shown that adult humans experience a range of positive emotions when shown images of newborns.

They feel less aggressive, act more gently and want to look after the babies they see. This applies above all to human babies, but a similar case can be made for young animals. Adults and children alike generally rate images of very young animals as cuter than those of older ones.

This tendency was confirmed by a study published in 2013 in the Dutch journal Behavioural Processes. The study demonstrated that people feel greater empathy towards young animals than towards adult ones.

Why do we love young animals so much? The reason is not yet clear, but there are two theories. According to the first, following the line laid down by Lorenz, it is because they remind us of human newborns, with whom they share certain physical characteristics, and whom we are biologically programmed to protect.

The second theory holds that our empathy with young animals enables us to bond more effectively with them, and that this trait may have been evolutionarily advantageous in the past, helping us to survive — although it is not clear how.

In any case, this preference for young animals appears to be closely linked to parental care. Species that invest a great deal of time and effort in raising their young to help them survive — including our own — find young animals more appealing than other animals do, such as reptiles and fish, which cease to concern themselves with their offspring once they have brought them into the world.