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 having had premarital sexual relations by the age of 20, whereas less than 20% in Japan and South Korea reported the same. While emerging adulthood exemplars are found mainly within the middle and upper classes of OECD countries, the stage of development still seems to occur across classes, with the main difference between different ones being length—on average, young people in lower social classes tend to enter adulthood two years before those in upper classes. While emerging adulthood occurs on a wide scale only in OECD countries, developing countries may also exhibit similar phenomena in certain population subgroups. In contrast