In primary and secondary school, pupils in the same class might differ substantially in age. Such differences are due to the distance between a student’s birthdate and the cutoff date (i.e., the date that determines the academic year or the grade to which the student is assigned). Recent scientific studies have shown that the relatively younger students in class perform more poorly, have fewer friends, and prefer to avoid face-to-face interactions with friends. These students are also more frequently bullied.
Click here for original story, The youngest pupils in the class are less satisfied with their lives
Source: Phys.org