An important study on the effects of smartphones on our cognitive ability.
Brain Drain: The Mere Presence of One’s Own Smartphone Reduces Available Cognitive Capacity
"The proliferation of smartphones represents a profound shift in the relationship between consumers and technology. Across human history, the vast majority of innovations have occupied a defined space in consumers’ lives; they have been constrained by the functions they perform and the locations they inhabit. Smartphones transcend these limitations. They are consumers’ constant companions, offering unprecedented connection to information, entertainment, and each other. They play an integral role in the lives of billions of consumers worldwide and, as a result, have vast potential to influence consumer welfare—both for better and for worse.
The present research identifies a potentially costly side effect of the integration of smartphones into daily life: smartphone-induced “brain drain.” We provide evidence that the mere presence of consumers’ smartphones can adversely affect two measures of cognitive capacity—available working memory capacity and functional fluid intelligence—without interrupting sustained attention or increasing the frequency of phone-related thoughts. Consumers who were engaged with ongoing cognitive tasks were able to keep their phones not just out of their hands, but also out of their (conscious) minds; however, the mere presence of these devices left fewer attentional resources available for engaging with the task at hand.
Further, we find that the effects of smartphone salience on available cognitive capacity are moderated by individual differences in the personal relevance of these devices (operationalized in terms of smartphone dependence); those who depend most on their devices suffer the most from their salience, and benefit the most from their absence. The role of dependence in determining mere presence effects suggests that similar cognitive costs would not be incurred by the presence of just any product, device, or even phone. We submit that few, if any, stimuli are both so personally relevant and so perpetually present as consumers’ own smartphones. However, we leave open the door for our insights to apply more broadly to future connective technologies that may become equally central to consumers’ lives as technology continues to advance."
https://www.journals.uchicago.edu/doi/full/10.1086/691462