As humans grow from infancy to old age there are major changes in the amount and kind of sleep experienced. Babies sleep a lot more than children and adults also have different sleep patterns and different stages of sleep. They tend to sleep about 16 hours a day. But their sleep is not continuous. By the age of six months a circadian rhythm has become established (one main sleep wake cycle). By the age of give, children have EEG patterns like those of adults but they are still sleeping more and having more REM activity. During childhood, it is not uncommon for children to experience a variety of sleep disorders such as sleep walking and night terrors.
During childhood, the need for sleep decrease, but in adolescence, it increases, to about nine of ten hours a night. Circadian rhythms also change so that teenagers feel naturally awake later at night and have more difficulty getting up early (a phase delay).
Adult sleep is typically about eight hours a night, with 25% REM sleep. Childhood parasomsineas are rarer in adulthood but there is an increasing frequency of other sleep disorders, such as insomnia and apnoea. With increased age, the pattern of sleep changes; REM sleep decreases to about 20% of total sleep time. Older people also experience a phase advance of circadian rhythms – feeling sleepier early in the evening and waking up earlier.
This approach to psychology is called the developmental approach and is important in highlighting the changes across a person’s lifespan.
One suggestion as to why babies’ sleep patterns are so different from those of adults is that their sleep is an adaptive mechanism to make their parents life easier – daytime sleep means that parents can get on with their chores which enhances survival. Infants’ greater amount of active/REM sleep may be explained in terms of the relative immaturity of the brain, and is related to the considerable amount of learning taking place....