According to studies
The best learning emerges in the context of supportive relationships that make learning challenging, engaging, and meaningful; social and emotional skills are critical to being a good student, citizen, and worker; and many different risky behaviors (e.g., drug use, violence, bullying, and drop out) can be prevented or reduced when multi-year, integrated efforts develop students’ social and emotional skills.
One of the reasons for which older children may have difficulties in compulsory schools is that they never really learned the above-mentioned skills in preschool.
Preschool provide pupils with lots of long-term benefits that will make children capable of negotiating their life, operating in a workplace, settling down and having a family in the future. In particular, children will reach the following skills:
Self-management; children gain the ability to understand, control and manage their feelings and reactions to different situations. This allow them to reflect on their emotional reactions, on hot to solve them and inhibit the impulsive response. This does not mean that a child should always be happy, brave and calm, but some children needs more struggle to calm down.
Social awareness; children learn to put themselves in other people’s shoes: they begin to understand others’ feelings, to share and to resolve conflicts. They also learn that we live in a multicultural society where there are lots of people having different linguistic and cultural backgrounds. As consequence, they also understand social and ethical norms of behaviours and how to be respectful;
Relationship skills; children learn how to interact in a right way and how to create close friendships with other pupils. Therefore, they learn to communicate clearly, cooperate, listen, offer their help and how to work in team;
Trust and independence; preschool gives children the opportunity to take some time away from their parents and get more familiar with the environment around them. In fact, “children who don’t attend preschool often face separation problems with their moms at the start of kindergarten and also encounter difficulty in following instructions, rules, and regulations” (KidsMatterAustralia, The five social and emotional competencies); one one side, this get kids become confident and independent, on he other side, it allows parents to work, stay more focused and also enjoy their time as adults.