ABSTRACT
Adolescence is the transition period between childhood and adulthood during which individuals gain independence and develop mature social goals. The age range of adolescence differs between countries and cultures, but it is generally agreed upon that, in Western societies, adolescence encompasses the period of approximately ages 10 to 22 years (Blakemore & Robbins, 2012; Crone & Dahl, 2012). The onset of adolescence commences at the start of puberty, which is the phase in life during which rapid increases in gonadal hormones result in changes in physical appearance, such as voice changes in boys and breast development in girls, but also behavioral and brain changes (Blakemore, Burnett, & Dahl, 2010). That is, it has been found previously that pubertal hormones have a massive infl uence on the developing brain structure and function (Peper & Dahl, 2013). Puberty thus marks the fi rst phase of adolescence and starts approximately around ages 10-11-years, on average 1.5 years earlier for girls than for boys, and lasts until approximately age 15-16 years (Blakemore et al., 2010). The second phase of adolescence (16-22 years) is characterized by the development of mature goals and gaining independence from parents. The end of adolescence is mostly culturally defi ned and is dependent on when individuals obtain a mature role in society (Crone & Dahl, 2012).
