The same conditions are necessary for a good and healthy development of animals. Their roots need to be solid. This means that newborns need good parenting from their own mother and in case of pets, good support from humans.
If these conditions are given, the animals can bloom and will be well adapted to their kind and human environment. A foal for example needs to grow up with it's peers in order to learn their own body and strength. In the meadows the natural play of the foals will teach them which behavior is appropriate and which isn't. Their mother will teach them how to be kind towards each other. Like a kindergarten.
This process of socialization is very important for their success and happiness in the future. With appropriate socialization, 'the roots' are solid ground and can be build on.
Ilonka, the old mare, missed out a part in this process. They moved her away too early from her mom and put her in a meadow all by herself... She must have felt lonely and deserted. However, this sad history left some marks on her behaviour in the daily interaction.
Despite of all this she is very sweet and nice to children and other horses. Although she always looks a bit sad and Ilonka finds it difficult to receive love from other horses. The paradox at present life is that almost all the horses on the farm where she lives are fond of her. Frequently there is a horse trying to show his or her affection to her. Ilonka simply doesn't know how to react ...
Notwithstanding the fact, that she missed out a part of her socialization process and her roots aren't solid, Ilonka is a very lovable and friendly horse.
This gives hope for (human) animals.