Messinis Stavros, 2012

During the last decades, an increased interest in co-sleeping has been noted. It seems to be an important phenomenon because it is connected with the social experiences in infancy . It is also linked with researches which illustrate the importance of considering the physical and social environment of the infant beyond sleep surfaces. For instance, concerning the physical environment, Burnham in 2000s noted that brightness of the light during the sleep influences circadian rhythms in very young infants and has an effect in their development. Moving from the physical to the social environment, the concern of co-sleeping is becoming increasingly important. Something else which makes the interest of co-sleeping very important is the fact that many studies show that parent - child co-sleeping is associated with sleep problems. Most of the sleeping problems include difficulties in falling asleep and waking up during the sleep. These difficulties concern behavioral or social and not medical problems.

Messinis Stavros, 2012

Bullying is thought to be one of the most prevalent types of school violence. Bullying perpetration and victimization was brought to the attention of researchers such as Dan Olweus, who referred to bullies as “whipping boys” in the 1970s. Olweus gave the following definition of bullying that continued to be consistently used up the early 2000s: “A student is being bullied or victimized when he or she is exposed, repeatedly and over time, to negative actions on the part of one or more other students” (Olweus, 1993:318). It often involves an imbalance of strength and power between the bully and the target and is repetitive in nature. Children and adolescents may experience isolated acts of aggression, but children who have been bullied live with the ongoing fear of recurring abuse from the bully, which is usually more damaging than an isolated and unpredicted aggressive event.