Smartphone Use for Business at Night Not So Smart?
Late evening use disrupts sleep and may hurt productivity, study suggests
Respondents who indicated having a greater degree of control over their job seemed to suffer less smartphone-related energy depletion the following morning, compared to those who felt their job control was generally low.
The second survey focused on 136 employees representing a wide range of fields, including retail, manufacturing, media and the health industry. Their average age was about 31.
More evenly split between men and women (54 percent versus 46 percent), participants responded to similar survey questions while also revealing how much they used other devices at night, including laptops, tablets and TVs.
The results of the second survey confirmed those of the first. An added finding was that work-related smartphone use at night had a notably larger negative impact on sleep and daytime work focus than night-time use of other devices.
"For example, although people would view TV after 9 p.m. for an average of 45 to 50 minutes per night, when we looked at the relationship between TV use and mental fatigue the next morning there really was none," Johnson said. "And I would guess that was because TV watching was not about work, whereas the smartphone use we looked at was."
"So we don't know what the affect of chatting in bed with friends for non-work social purposes might be," he acknowledged. "It could even be good, helping people detach before sleep and even perhaps counterbalancing the problematic physiological impact of phone light."
"But regardless, my recommendation is to not take the smartphone to bed," Johnson said. "It's an individual choice, and I know some days that can be hard. But this study highlights that at least with respect to work use there are consequences for the next day to having that phone on at night."
Jeffrey Hall, an associate professor in the department of communication studies at the University of Kansas, contends that concern about smartphones is just the latest version of the so-called "CrackBerry" phenomenon, a hot topic only a few years back.
"The idea then was that workers were almost addicted to their BlackBerrys. And now the widespread adoption of smartphones is exacerbating that trend," Hall said. "The problem is that the benefit of always being available also comes with expectations. We feel obligated to always be reachable, to respond immediately and to get fast replies. It's a new and transformative cultural norm, which we're navigating without clearly defined boundaries."