Scientists from the University of Toronto studied the habits of two groups of people: 435 young adults between the ages of 17 and 38, and 297 older adults, aged 59 to 79.
On the flip side, all but 7% of the older group identified themselves as early birds. This eventual switch in the biological clock could be why older adults are happier, The New York Daily News reports.
“We found that older adults reported greater positive emotion than younger adults, and older adults were more likely to be morning type-people than younger adults,” study researcher Renee Bliss said.
“The ‘morningness’ was associated with greater happier emotions in both age groups,” she added. The study also claims that early risers also reported feeling healthier than their late-sleeping counterparts.
The researchers add that earlier hours could make people happier because they’re more in line with societal expectations.
“Evening people may be more prone to social jet lag,” Bliss explains. “This means that their biological clock is out of sync with the social clock. Society’s expectations are far more organized around a morning-type person’s schedule.”
The results of the study showed that people usually consider themselves to be early persons by the time they turn 60. All but 7% of the younger group identified themselves as night owls.
By the way, older people are also reported to be lousy sleepers, and aother study suggests it might all be in their heads, at least for many of them.
Elizabeth Klerman of Brigham and Women’s Hospital and the Harvard Medical School has conducted a controlled study of 18 subjects ages 60 to 76 and 35 younger subjects, ages 18 to 32, all healthy and not on medication that might affect sleep.
The subjects were regularly instructed to lie quietly with their eyes closed and to try to sleep, for as much as 16 hours daily for several days in a row. They had all the time in the world. The bottom line was that the seniors simply needed less sleep — about 1.5 hours less, writes Live Science.
The results also showed that younger people slept for an average of 9 hours compared to 7.5 for older people, said Klerman and her colleague Derk-Jan Dijk of the Surrey Sleep Research Centre in England.
“There are definitely older people with insomnia,” Klerman said. “However there may also be some older people who ‘create’ insomnia if they believe that they ‘need’ 8 to 9 hours of sleep and therefore spend more time in bed (lying awake) than needed to achieve the amount of sleep ‘needed.'”
“It’s also possible that they sleep less even when given the opportunity for more sleep because of age-related changes in the ability to fall asleep and remain asleep,” she added, noting that the new results apply only to healthy individuals taking no medication and having no medical conditions or sleep disorders.
The same study found one more age effect: older people need more time to fall asleep.
The researchers set 60 years old as the starting point for their older subjects to ensure a clear distinction from the younger group, but it is possible that the declining capacity to sleep could reach back into the middle-age years too, Klerman said.
“My expectation is that the change is gradual and there is no time point at which we ‘age,'” she said. “Sleep changes from infancy, through childhood, puberty, young adulthood and middle-age until we die.”