The reason behind our admiration of toddlers and animals has been first propounded by an Austrian biologist and ethologist Konrad Lorenz, who did an extensive research in 1949 on this trait of human behavior, and coined it the term 'Baby Schema' or 'Kindchenschma'. He concluded that, it is a set of physical traits, especially the round big eyes, big head, small body, and tender movements that attracts the attention of a person, and he/she develops a feeling of affection towards it.
Every person has a different definition for cuteness and likability. A person gets attracted to those animals or babies with whom he feels like getting along or communicating. Another research in this field has been performed by two Yale University psychologists, Rebecca Dyer and Oriana Aragon, who tried to unearth the reason behind the outward behavior or responses of people when they find something admiring.
According to the studies carried out by psychologists Rebecca Dyer and Oriana Aragon, it is pent-up emotion, excitement, and a higher aggression that makes a person feel like squeezing pups or cubs and babies. This phenomenon is termed as 'Cuteness Aggression'. The sight of an animal or a baby doing sweet, crazy gestures gives a relieving effect to the emotions of humans, and we feel happy and light.
A possible reason behind an involuntary pull towards meek, delicate babies is because of the release of the Oxytocin hormone, which encourages a person to show his feelings of love, affection, and tenderness towards the things which he enjoys the most, around whom he identifies his self, and feels emotionally secured.
Studies on human behavior concluded that people, when coming in contact with innocent beings like animals or human kids, feel extremely happy, and this positive feeling of happiness is so excessive that it finds expression in a negative way, like squeezing, rigorous cuddling, and pulling the cheeks. It is excess of happiness becoming difficult to contain.
The eyes are the most effective way through which little ones express their inner innocence and purity. They are the most appealing thing about them, second being their staggering, small footsteps. The idea of 'Baby Schema' is used in many graphics and animations to make cartoon characters more appealing and communicating.