Facial expression responsible for controlling the expression differ in each case. Voluntary facial expressions are often socially conditioned and follow a cortical route in the brain. Conversely, involuntary facial expressions are believed to be innate and follow a subcortical route in the brain. Facial recognition is often an emotional experience for the brain and the amygdala is highly involved in the recognition process. The eyes are often viewed as important features of facial expressions. Aspects such as blinking rate can possibly be used to indicate whether a person is nervous or whether he or she is lying. Also, eye contact is considered
Emerging adulthood and early adulthood 25 years of age where adolescents become more independent and explore various life possibilities. Arnett argues that this developmental period can be isolated from adolescence and young adulthood. Emerging adulthood is a new demographic, is contentiously changing, and some believe that twenty-somethings have always struggled with "identity exploration, instability, self-focus, and feeling in-between". Arnett called this period "roleless role" because emerging adults do a wide variety of activities, but are not constrained by any sort of "role requirements". The developmental theory is highly controversial within the developmental field, and developmental psychologists argue over the legitimacy of Arnett's theories and methods.