Decoded: Here's why you can't live without your smartphoneFeb 12 (AZINS) Scientists have explained why we are tempted to pick up our smartphones and start scrolling through social media or text messages at any moment, even when the devices disrupt our face-to-face social interactions.

Smartphones have become a constant companion for many of us. In a recent study by the Pew Research Center, nearly 50 per cent of adults reported they "couldn't live without" their phones.

Researchers at the University of Arizona and Wayne State University in the US examined existing research on "technoference," or the potential interference smartphones and other technologies can have in our face-to-face social interactions.

They propose an explanation for why humans are so drawn to their smartphones, even when the devices take us out of the moment in our close relationships.

It is because of our evolutionary history and the fact that humans are hard-wired to connect with others, according to the study published in the journal Perspectives on Psychological Science.

In the course of evolutionary history, we have relied on close relationships with small networks of family and friends for survival as individuals and as a species, researchers said.

These relationships were based on trust and cooperation, which is built when people disclose personal information about themselves and are responsive to others, they said.Smartphones, and the constant access they provide to text messaging and social media, make it easier than ever for people to disclose personal information and respond to others in their social networks.

These networks are much larger and more far-flung than those of our ancestors.

"The draw or pull of a smartphone is connected to very old modules in the brain that were critical to our survival, and central to the ways we connect with others are self-disclosure and responsiveness," said David Sbarra, a psychology professor at the University of Arizona.

"Evolution shaped self-disclosure and responsiveness in the context of small kin networks, and we now see these behaviours being cued more or less constantly by social networking sites and through our phones," Sbarra said in a statement.

"We now have the outer-most edges of our social network cue us for responsiveness. Look no further than the next person you see scrolling through Facebook and mindlessly hitting the 'like' button while his kid is trying to tell him a story," he said.

The researchers suggest that there may be an evolutionary mismatch between smartphones and the social behaviours that help form and maintain close social relationships.

"Smartphones and their affordances create new contexts for disclosing information about who we are and for being responsive to others, and these virtual connections may have downstream unwanted effects on our current relationships," Sbarra said.

"When you are distracted into or by the device, then your attention is divided, and being responsive to our partners -- an essential ingredient for building intimacy -- requires attention in the here and now," he said.

Divided attention, researchers said, may lead to relationship conflict. For example, a study of 143 married women, more than 70 per cent of whom reported that mobile phones frequently interfere in their relationships.